Control method and non-transitory computer-readable recording medium for comparing medical images

ABSTRACT

Similar medical images having a predetermined similarity to a region of interest in a medical image to be interpreted are received from a case search system. A display screen on which the received similar medical images are displayed is displayed on a display. The display screen includes display frames within which similar medical images are displayed. In response to an instruction for enlarging the similar medical images, corresponding regions of interest in the similar medical images are enlarged and displayed with the sizes of the display frames maintained unchanged on the display screen. In response to an instruction for causing a selected similar medical image among the enlarged and displayed similar medical images to move within a corresponding display frame, the other unselected similar medical image(s) is caused to move within a corresponding display frame synchronously with the movement of the selected similar medical image in the same movement direction.

BACKGROUND

1. Technical Field

The present disclosure relates to a control method for controlling aninformation terminal for searching for similar medical images that aresimilar to a medical image to be interpreted, and to a non-transitorycomputer-readable recording medium.

2. Description of the Related Art

Medical imaging devices such as computed tomography (CT) and magneticresonance imaging (MRI) devices have been developed and used widely inrecent years. The advent of CT, MRI, and the like has enabledacquisition of a large number of high-definition digital medical images.Medical images interpreted by physicians are sequentially accumulatedtogether with interpretation reports in a picture archiving andcommunication system (PACS). For instance, as disclosed in JapaneseUnexamined Patent Application Publication No. 2008-257292, a techniquefor image retrieval has been being developed. In this technique,previous medical images that are similar to a medical image to beinterpreted are searched for in the records of previous clinical casesaccumulated in the PACS for the reference of new interpretation.

However, further improvements have been needed.

SUMMARY

One non-limiting and exemplary embodiment provides a furtherimprovement.

In one general aspect, the techniques disclosed here feature a controlmethod for controlling an information terminal for access to a casesearch system that searches for a medical image with reference to amedical image database having medical images registered therein. Theinformation terminal includes a display and a computer, and a targetmedical image that is a medical image to be interpreted and that isselected from among candidate medical images to be interpreted isdisplayed on the display. The control method includes causing thecomputer of the information terminal to detect designation informationindicating a region of interest included in the target medical image;causing the computer of the information terminal to receive from thecase search system, in accordance with the region of interest indicatedby the designation information, a plurality of similar medical imageseach having a feature value having a predetermined similarity to afeature value of the region of interest, each of the plurality ofsimilar medical images including a corresponding region of interestwhich corresponds to the region of interest; causing the computer of theinformation terminal to display a display screen on the display, thedisplay screen being a screen on which a number of similar medicalimages that is less than or equal to a predetermined value among thereceived plurality of similar medical images are displayed, the displayscreen including a number of display frames that is equal to thepredetermined value to display the similar medical images; causing thecomputer of the information terminal to, in response to detection of aninstruction for enlarging the similar medical images being displayed onthe display screen, enlarge and display the corresponding regions ofinterest included in the similar medical images while maintaining sizesof the display frames unchanged on the display screen; and causing thecomputer of the information terminal to, in response to detection of aninstruction for causing a selected similar medical image selected fromamong the enlarged and displayed similar medical images to move within acorresponding display frame among the display frames, cause anunselected similar medical image other than the selected similar medicalimage to move synchronously with the movement of the selected similarmedical image within a display frame corresponding to the unselectedsimilar medical image among the display frames in a movement directionidentical with a movement direction in which the selected similarmedical image moves. A ratio of a movement distance by which theselected similar medical image moves to a movement distance by which theunselected similar medical image moves corresponds to a ratio of an areaof the corresponding region of interest included in the selected similarmedical image to an area of the corresponding region of interestincluded in the unselected similar medical image.

It should be noted that general or specific embodiments may beimplemented as a system, a method, an integrated circuit, a computerprogram, a computer-readable recording medium, or any selectivecombination thereof. Examples of the computer-readable recording mediuminclude a non-volatile recording medium such as a compact disc-read onlymemory (CD-ROM).

In an aspect of the present disclosure, a further improvement may beachievable.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall configuration diagram of a hospital informationsystem in which an information terminal according to a first embodimentis used;

FIG. 2 is a block diagram illustrating the configuration of theinformation terminal, a medical information management system, and acase search system;

FIG. 3 illustrates external views of two displays;

FIG. 4 is a diagram illustrating an example configuration of animplementation of the information terminal;

FIG. 5 is a diagram illustrating an example of a basic screen displayedon a display immediately after a similar case search application isstarted on the information terminal;

FIG. 6 is a diagram illustrating an example of a basic screen displayedon a display immediately after the similar case search application isstarted on the information terminal;

FIG. 7 is a diagram illustrating a display area for a certain similarcase extracted from among similar cases displayed in a case displayarea;

FIG. 8 is a diagram illustrating a basic screen obtained when one of thethumbnail images displayed in the case display area is selected;

FIG. 9 is a diagram illustrating a basic screen obtained when athumbnail image different from that illustrated in FIG. 8 is selectedamong the thumbnail images displayed in the case display area;

FIG. 10 is a diagram illustrating a basic screen obtained when all thethumbnail images displayed in the case display area are enlarged;

FIG. 11 is a diagram illustrating a basic screen, different from thatillustrated in FIG. 10, which is obtained when all the thumbnail imagesdisplayed in the case display area are enlarged;

FIG. 12 is a diagram illustrating a basic screen obtained when one ofthe thumbnail images displayed in the case display area is selectedafter the thumbnail images are enlarged and displayed;

FIG. 13 is a diagram schematically illustrating a drag operationperformed by a user while a basic screen is being displayed;

FIG. 14 is a diagram illustrating a basic screen obtained when displayareas in thumbnail images displayed in the case display area are causedto move;

FIG. 15 is a diagram schematically illustrating a drag operation furtherperformed by the user while the basic screen illustrated in FIG. 14 isbeing displayed;

FIG. 16 is a diagram illustrating a basic screen obtained when thedisplay area in the thumbnail image displayed in the case display areais moved by the drag operation illustrated in FIG. 15;

FIG. 17 is an enlarged view of a disease list display area;

FIG. 18 is a diagram illustrating a basic screen on which similar casesare refined according to “mycosis”;

FIG. 19 is a diagram illustrating a basic screen on which similar casesare refined according to “metastatic lung cancer”;

FIG. 20 is an enlarged view of a distribution list display area;

FIG. 21 is a diagram illustrating the distribution list display area inwhich the checkbox for “bilateral” is checked;

FIG. 22 is a diagram illustrating a basic screen on which refinement isperformed in accordance with bilateral lesion distribution;

FIG. 23 is a diagram illustrating the distribution list display area inwhich the checkbox for “bronchial” is checked;

FIG. 24 is a diagram illustrating a basic screen on which refinement isperformed in accordance with bronchial lesion distribution;

FIG. 25 is a diagram illustrating the distribution list display area inwhich the checkbox for “subpleural” is checked;

FIG. 26 is a diagram illustrating a basic screen on which refinement isperformed in accordance with subpleural lesion distribution;

FIG. 27 is diagram schematically illustrating a drag operation performedby a user while the basic screen illustrated in FIG. 24 is beingdisplayed;

FIG. 28 is a diagram schematically illustrating a drag operationperformed by a user while the basic screen illustrated in FIG. 26 isbeing displayed;

FIG. 29 is a diagram illustrating the data configuration of patientinformation;

FIG. 30 is a diagram illustrating the data configuration of testinformation registered in the patient information illustrated in FIG.29;

FIG. 31 is a diagram illustrating the data configuration of a medicalimage database;

FIG. 32 is a diagram illustrating the data configuration of a diagnosticreport;

FIG. 33 is a diagram illustrating the data configuration of similar casedata;

FIG. 34 is a diagram schematically illustrating a region of interest seton a slice image;

FIG. 35 is a sequence diagram illustrating a process performed during aperiod in which the information terminal obtains a case to be diagnosedfrom the medical information management system and then sends a similarcase search request to the case search system and the case search systemreceives the similar case search request;

FIG. 36 is a view of a test list screen;

FIG. 37 is a view of the test list screen after a test is selected;

FIG. 38 is a diagram illustrating a slice image displayed in a medicalimage viewer when a user selects a series;

FIG. 39 is a sequence diagram illustrating a process performed during aperiod in which, after receiving a similar case search request, the casesearch system returns similar case search results to the informationterminal;

FIG. 40 is a diagram illustrating the data configuration of display boxmanagement information;

FIG. 41 is a diagram illustrating a basic screen having a layout area inwhich display boxes are set in three rows and two columns;

FIG. 42 is a diagram illustrating an example of layout managementinformation;

FIG. 43 is a diagram illustrating an example of the layout managementinformation;

FIG. 44 a flowchart illustrating the details of an initial basic screengeneration process illustrated in S670 in FIG. 39;

FIG. 45 is a flowchart illustrating the processing of S1500 illustratedin FIG. 44;

FIG. 46 is a diagram illustrating the data configuration of a diseaselist generated in S1300 in FIG. 44;

FIG. 47 is a diagram illustrating a first example display of the diseaselist display area;

FIG. 48 is a diagram illustrating a second example display of thedisease list display area;

FIG. 49 is a diagram illustrating a third example display of the diseaselist display area;

FIG. 50 is a diagram illustrating a screen transition that occurs in thedisease list display area illustrated in FIG. 48;

FIG. 51 is a diagram illustrating the data configuration of adistribution list generated in S1400 in FIG. 44;

FIG. 52 is a diagram illustrating a distribution list display areagenerated using the distribution list illustrated in FIG. 51;

FIG. 53 is a block diagram of an information terminal, a medicalinformation management system, and a case search system according to anembodiment in which the case search system extracts an image feature;

FIG. 54 is a sequence diagram illustrating a process performed during aperiod in which, after the information terminal obtains a case to bediagnosed from the medical information management system, the casesearch system receives a similar case search request;

FIG. 55 is a sequence diagram illustrating a process performed during aperiod in which, after receiving the similar case search request, thecase search system returns similar case search results to theinformation terminal;

FIG. 56 is a flowchart illustrating a process for enlarging thumbnailimages displayed in the case display area;

FIG. 57 is a flowchart illustrating a process in a subroutine of S4400in FIG. 56;

FIG. 58 is a diagram schematically illustrating reference thumbnailimages obtained before and after an enlargement process is performed andenlargement-intended thumbnail images obtained before and after anenlargement process is performed;

FIG. 59 is a flowchart illustrating a process in a subroutine of S4500in FIG. 56;

FIG. 60 is a diagram schematically illustrating the relationship betweenan enlargement factor and a display area;

FIG. 61 is a sequence diagram illustrating a process performed during aperiod in which, after thumbnail images obtained as a result of thesimilar case search are enlarged and displayed on a display of theinformation terminal, a display area is changed;

FIG. 62 is a block diagram illustrating a detailed configuration of anenlarged image generation unit;

FIG. 63 is a diagram schematically illustrating the movement of adisplay area across an enlarged thumbnail image;

FIG. 64 is a flowchart illustrating a process for changing the displayarea for an enlarged thumbnail image;

FIG. 65 is a block diagram illustrating another detailed configurationof the enlarged image generation unit, which is different from thatillustrated in FIG. 62;

FIG. 66 is a flowchart illustrating a display area changing processperformed using the configuration illustrated in FIG. 65;

FIG. 67A is a diagram illustrating an example of an enlarged thumbnailimage;

FIG. 67B is a diagram illustrating an entire thumbnail image before thethumbnail image illustrated in FIG. 67A is enlarged;

FIG. 67C is a diagram schematically illustrating the movement of adisplay area across a thumbnail image before enlargement;

FIG. 68 is a flowchart illustrating a thumbnail image enlargementprocess performed when a user operates a scrollbar after an enlargedthumbnail image is displayed in the case display area;

FIG. 69 is a diagram illustrating a basic screen on which enlargedthumbnail images are being displayed in the case display area;

FIG. 70 is a diagram illustrating a basic screen on which enlargedthumbnail images have moved from the state illustrated in FIG. 69;

FIG. 71 is a flowchart illustrating a process performed when adistribution of lesions displayed in the distribution list display areais selected;

FIG. 72 is a diagram illustrating the data configuration of similar casedata that additionally includes pleural area information;

FIG. 73 is a diagram depicting a pleural area;

FIG. 74 is a diagram illustrating a basic screen on which thumbnailimages of similar cases retrieved as a result of the similar case searchare being displayed in the case display area according to a secondembodiment;

FIG. 75 is a diagram illustrating a basic screen obtained when a secondinstruction button is selected by a user;

FIG. 76 is a diagram illustrating a basic screen obtained when a thirdinstruction button is selected by a user;

FIG. 77 is a diagram schematically illustrating a drag operationperformed by a user while the basic screen (FIG. 75) obtained when thesecond instruction button is selected by the user is being displayed;

FIG. 78 is a diagram schematically illustrating a drag operationperformed by a user while the basic screen (FIG. 76) obtained when thethird instruction button is selected by the user is being displayed;

FIG. 79 is a flowchart illustrating an enlargement process performedwhen a user selects an enlargement factor change button;

FIG. 80 is a block diagram illustrating a detailed configuration of anenlarged image generation unit according to the second embodiment;

FIG. 81 is a flowchart illustrating a process for changing the displayarea for an enlarged thumbnail image;

FIG. 82 is a block diagram illustrating another detailed configurationof the enlarged image generation unit, which is different from thatillustrated in FIG. 80;

FIG. 83 is a sequence diagram illustrating a process performed during aperiod in which, after the case search system transmits similar casesearch results to the information terminal, the enlargement factorchange button is selected on the information terminal and enlargedthumbnail images are displayed on the display of the informationterminal;

FIG. 84 is a flowchart illustrating pre-processing executed in the casesearch system and the process illustrated in FIG. 83;

FIG. 85 is a diagram illustrating the data configuration of enlargedthumbnail data;

FIG. 86 is a sequence diagram focusing on the sequence diagramsillustrated in FIG. 35 and FIG. 39 at the application level; and

FIG. 87 is a sequence diagram focusing on the sequence diagramsillustrated in FIG. 54 and FIG. 55 at the application level.

DETAILED DESCRIPTION

Underlying Knowledge of Present Disclosure

First, a description will be given of issues pertaining to an aspect ofthe present disclosure.

Japanese Unexamined Patent Application Publication No. 2008-257292(hereinafter referred to as “Patent Literature 1”) discloses animage-based diagnosis supporting apparatus that presents images ofclinical cases which are useful for judging a disease or disorder(hereinafter referred to simply as a “disease”) or presents statisticalinformation and the like on the disease for image-based diagnosis whichis based on an image to be used for diagnosis (hereinafter referred toas a “diagnostic image”). The image-based diagnosis supporting apparatusdisplays a search result screen which shows the diagnostic image andinformation on typical cases of individual diseases. Specifically, thesearch result screen shows (i) images of typical cases of the top threeranked diseases A, D, and G, (ii) similarities to the diagnostic image,the numbers of registered cases, and the numbers of typical cases forthe individual diseases, (iii) the number of search results (or thetotal number of diseases found as a result of the search), and (iv) a“next page” soft button or the like for accessing information on theother diseases not shown on the current screen (see paragraphs [0062] to[0063] and FIG. 6(E) in Patent Literature 1).

On the other hand, Patent Literature 1 does not describe the enlargementof the images of the typical cases displayed on the search result screenor the movement of the images of the typical cases within individualdisplay frames after enlargement. Since Patent Literature 1 does notdisclose even the enlargement of images of typical cases or the movementof the images of the typical cases within individual display framesafter enlargement, a devised method such as causing each of the imagesof the typical cases to move in accordance with the size of a lesionarea included in the image of the typical case is also not disclosed.

Japanese Unexamined Patent Application Publication No. 2004-215041(hereinafter referred to as “Patent Literature 2”) discloses an imageprocessing device capable of performing high-usability comparisonbetween a plurality of images. On a screen displayed by the imageprocessing device, two images to be compared are displayed in imagedisplay areas 51a and 51b (see FIGS. 7(C) to 7(F), FIGS. 8(C) to 8(F),and FIGS. 9(C) to 9(D) in Patent Literature 2). The image processingdevice is configured such that, when the image displayed in the imagedisplay area 51a is caused to move within the image display area 51a,the image displayed in the image display area 51b is also caused to movewithin the image display area 51b synchronously (see paragraphs [0060],[0072], [0088], and [0100] in Patent Literature 2).

In Patent Literature 2, however, the plurality of images to be comparedare assumed to be images captured by a personal user with their digitalcamera or the like (paragraphs [0002] to [0005] in Patent Literature 2).Comparison between medical images having lesion areas is not describedin Patent Literature 2. Accordingly, it may be difficult to simply applythe method described in Patent Literature 2 to a technique for examininglesion areas in medical images. Accordingly, Patent Literature 2 doesnot also disclose a devised method such as causing medical images tomove synchronously in accordance with the size of lesion areas in themedical images.

OOSAWA et al. discloses, in “Development of ‘SYNAPSE Case Match’,Content-based Image Retrieval System for Supporting Image Diagnosis”,FUJIFILM RESEARCH & DEVELOPMENT, FUJIFILM Corporation, Mar. 27, 2013,No. 58, pp. 11-14 (hereinafter referred to as “Non-Patent Literature1”), a similar-case search system that uses a function to search forprevious similar cases by using the image of a lesion to immediatelyextract and present exact information based on clinical knowledgeaccumulated in the PACS described above or the like to assist thephysician in image-based diagnosis. Specifically, in the disclosedsystem, a plurality of clinical case images containing a lesion having afeature similar to that of a lesion in a test image are retrieved anddisplayed in order of similarity. Then, one reference clinical caseimage is selected from among the plurality of displayed clinical caseimages and is displayed along with the test image (Section 2.2, “SystemFeatures”, on page 12 and FIG. 3 in Non-Patent Literature 1).

However, the system disclosed in Non-Patent Literature 1 does notinvolve the enlargement of displayed clinical case images or themovement of the clinical case images within individual frames afterenlargement. Since Non-Patent Literature 1 does not disclose even theenlargement of clinical case images or the movement of the clinical caseimages within individual frames after enlargement, a devised method suchas causing each of images of typical cases to move in accordance withthe size of a lesion area included in the image of the typical case isalso not disclosed.

In the examination of a lesion appearing in a medical image to beinterpreted for which a disease name has not been specified, it isconsidered effective to refer to medical images similar to the medicalimage to be interpreted among other medical images for which diseasenames have been specified. When such a system is established, however, alarge number of medical images are registered in the medical imagedatabase described above. In this case, it is still desirable toeffectively provide the physician with similar medical images to bereferenced for diagnosis using the medical image to be interpreted.

In light of the foregoing discussion, the following aspects areprovided.

An aspect of the present disclosure provides a control method forcontrolling an information terminal for access to a case search systemthat searches for a medical image with reference to a medical imagedatabase having medical images registered therein. The informationterminal includes a display and a computer, and a target medical imagethat is a medical image to be interpreted and that is selected fromamong candidate medical images to be interpreted is displayed on thedisplay. The control method includes causing the computer of theinformation terminal to detect designation information indicating aregion of interest included in the target medical image; causing thecomputer of the information terminal to receive from the case searchsystem, in accordance with the region of interest indicated by thedesignation information, a plurality of similar medical images eachhaving a feature value having a predetermined similarity to a featurevalue of the region of interest, each of the plurality of similarmedical images including a corresponding region of interest whichcorresponds to the region of interest; causing the computer of theinformation terminal to display a display screen on the display, thedisplay screen being a screen on which a number of similar medicalimages that is less than or equal to a predetermined value among thereceived plurality of similar medical images are displayed, the displayscreen including a number of display frames that is equal to thepredetermined value to display the similar medical images; causing thecomputer of the information terminal to, in response to detection of aninstruction for enlarging the similar medical images being displayed onthe display screen, enlarge and display the corresponding regions ofinterest included in the similar medical images while maintaining sizesof the display frames unchanged on the display screen; and causing thecomputer of the information terminal to, in response to detection of aninstruction for causing a selected similar medical image selected fromamong the enlarged and displayed similar medical images to move within acorresponding display frame among the display frames, cause anunselected similar medical image other than the selected similar medicalimage to move synchronously with the movement of the selected similarmedical image within a display frame corresponding to the unselectedsimilar medical image among the display frames in a movement directionidentical with a movement direction in which the selected similarmedical image moves. A ratio of a movement distance by which theselected similar medical image moves to a movement distance by which theunselected similar medical image moves corresponds to a ratio of an areaof the corresponding region of interest included in the selected similarmedical image to an area of the corresponding region of interestincluded in the unselected similar medical image.

According to this aspect, first, the corresponding regions of interestincluded in the similar medical images being displayed on the displayscreen are enlarged with the sizes of the respective display framesbeing maintained unchanged. Thus, even if a display area for each of thesimilar medical images is constrained to fall within the correspondingone of the display frames, the corresponding region of interest includedin the similar medical image is enlarged. This may enable a user toefficiently observe a desired portion in each of the similar medicalimages.

Then, in response to detection of an instruction for causing a selectedsimilar medical image selected from among the enlarged similar medicalimages to move within a corresponding the display frame among thedisplay frames, an unselected similar medical image other than theselected similar medical image is caused to move synchronously with themovement of the selected similar medical image within a display framecorresponding to the unselected similar medical image in a movementdirection identical with the movement direction of the selected similarmedical image. That is, in response to detection of an instruction forcausing the selected similar medical image to move, not only oneselected similar medical image among the similar medical images beingdisplayed on the display screen is caused to move. Rather than this, theunselected similar medical image is caused to move within the displayframe within which the unselected similar medical image is beingdisplayed, in a movement direction identical with the movement directionof the selected similar medical image.

Accordingly, the user may be able to efficiently observe, in addition tothe corresponding region of interest, surrounding areas of thecorresponding region of interest for the similar medical images beingdisplayed on the display screen. For example, a secondary lesion may bepresent around the corresponding region of interest. According to thisaspect, the user may be able to efficiently observe a desired portion ineach of the similar medical images being displayed on the displayscreen.

In this aspect, therefore, in response to a single operation of causingthe selected similar medical image to move, the unselected similarmedical image is also caused to move synchronously with the movement ofthe selected similar medical image. This may enable the user to observedesired portions in one batch for not only the corresponding region ofinterest but also surrounding areas of the corresponding region ofinterest in each of the similar medical images being displayed on thedisplay screen.

Consequently, it may be possible to eliminate the need for the operationto cause the similar medical images being displayed on the displayscreen being to separately move, making the physician concentrate theirattention on the medical treatment decision. Accordingly, the accuracyof medical treatment decision may be effectively improved.

In addition, the area of the corresponding region of interest includedin the selected similar medical image may not necessarily be equal tothe area of the corresponding region of interest included in theunselected similar medical image. For example, the area of thecorresponding region of interest included in the selected similarmedical image may be larger than the area of the corresponding region ofinterest included in the unselected similar medical image. In this case,if the movement distance by which the selected similar medical imagemoves (hereinafter also referred to as the movement distance of theselected similar medical image) is equal to the movement distance bywhich the unselected similar medical image moves (hereinafter alsoreferred to as the movement distance of the unselected similar medicalimage), as a result of movement of the unselected similar medical image,the corresponding region of interest included in the unselected similarmedical image moves a large amount. Consequently, a larger number ofsurrounding areas away from the corresponding region of interestincluded in the unselected similar medical image appear. In general, asecondary lesion is more likely to be present in a surrounding areaclose to the corresponding region of interest included in the unselectedsimilar medical image. For this reason, if, as a result of movement ofthe unselected similar medical image, a surrounding area away from thecorresponding region of interest included in the unselected similarmedical image appears, a secondary lesion may fail to be detected.

According to this aspect, the ratio of the movement distance of theselected similar medical image to the movement distance of theunselected similar medical image corresponds to the ratio of the area ofthe corresponding region of interest included in the selected similarmedical image to the area of the corresponding region of interestincluded in the unselected similar medical image.

Accordingly, for example, even if the area of the corresponding regionof interest included in the selected similar medical image is largerthan the area of the corresponding region of interest included in theunselected similar medical image, the movement distance of the selectedsimilar medical image is not equal to the movement distance of theunselected similar medical image. This may prevent a surrounding areaaway from the corresponding region of interest included in theunselected similar medical image from appearing as a result of movementof the unselected similar medical image.

In this aspect, consequently, it may be possible to reduce the risk ofsecondary lesions failing to be detected without the need for theoperation to cause the similar medical images being displayed on thedisplay screen to separately move, making the physician concentratetheir attention on the medical treatment decision. Accordingly, theaccuracy of medical treatment decision may be effectively improved.

In addition, in the aspect described above, for example, in a case wherethe area of the corresponding region of interest included in theselected similar medical image is larger than the area of thecorresponding region of interest included in the unselected similarmedical image, the movement distance by which the unselected similarmedical image moves may be made shorter than the movement distance bywhich the selected similar medical image moves.

In addition, in the aspect described above, for example, the targetmedical image may have attached information that does not includedisease information on a name of a disease of a lesion displayed in thetarget medical image, and each of the received plurality of similarmedical images may have attached information that includes diseaseinformation on a name of a disease of a lesion displayed in the image.

According to this aspect, when observing the target medical image andspecifying the name of a disease of a lesion displayed in the targetmedical image, referring to similar medical images indicating lesionsfor which disease names have been specified may contribute to animprovement in diagnosis accuracy.

In addition, in the aspect described above, for example, the displayscreen may include a first display area in which the target medicalimage is displayed, and a second display area that includes the displayframes, the number of which is equal to the predetermined value.

According to this aspect, when observing the target medical image andspecifying the name of a disease of a lesion displayed in the targetmedical image, comparing the target medical image and the similarmedical images on the same display screen may contribute to animprovement in diagnosis accuracy.

In addition, in the aspect described above, for example, the similarmedical images, the number of which is less than or equal to thepredetermined value, among the received plurality of similar medicalimages may be displayed in the display frames in order of decreasingsimilarity to the target medical image.

According to this aspect, when comparing the target medical image andthe similar medical images, displaying the received plurality of similarmedical images in order of decreasing similarity to the target medicalimage may enable a user to compare the similar medical images with thetarget medical image in order of decreasing similarity. Accordingly, theuser may be able to efficiently specify the name of the disease of thelesion displayed in the target medical image, which may contribute to animprovement in diagnosis accuracy.

In addition, in the aspect described above, for example, the controlmethod may further include causing the computer of the informationterminal to transmit information indicating a feature value of theregion of interest to the case search system; and causing the computerof the information terminal to receive from the case search system asimilar medical image having a feature value having the predeterminedsimilarity to the feature value of the region of interest.

In addition, in the aspect described above, for example, the controlmethod may further include causing the computer of the informationterminal to transmit the target medical image and the designationinformation indicating the region of interest to the case search system;and causing the computer of the information terminal to receive from thecase search system a similar medical image having a feature value havingthe predetermined similarity to a feature value of the region ofinterest, which is obtained from the target medical image and thedesignation information.

In addition, in the aspect described above, for example, the targetmedical image may be a medical image of a lung, and each of the similarmedical images may be a medical image of a lung. The display screen mayinclude first distribution information for selection of a similarmedical image in which the corresponding region of interest belongs to apredetermined first range indicating that a size of the correspondingregion of interest is wide relative to the lung area, seconddistribution information for selection of a similar medical image inwhich the corresponding region of interest belongs to a predeterminedsecond range lower than first range, the second range indicating that asize of the corresponding region of interest is a portion of a lungarea, and third distribution information for selection of a similarmedical image in which the corresponding region of interest includes apleura. The computer of the information terminal may be caused to, inresponse to detection that distribution information has been selectedamong the first distribution information, the second distributioninformation, and the third distribution information, select a similarmedical image corresponding to the selected distribution information andto display the selected similar medical image on the display screen.

According to this aspect, it may be possible to further classify aplurality of similar medical images displayed on the display screenaccording to the distribution type of the corresponding region ofinterest. This may enable the user to efficiently select, for example, asimilar medical image with a similar symptom to the region of interestincluded in the target medical image from among a large number ofdisplayed similar medical images.

In addition, in the aspect described above, for example, the computer ofthe information terminal is caused to in response to detection that thefirst distribution information has been selected, display a similarmedical image corresponding to the first distribution information in acorresponding display frame among the display frames with an initialdisplay size; in response to detection that the second distributioninformation has been selected, display a similar medical imagecorresponding to the second distribution information in a correspondingdisplay frame among the display frames in such a manner that the similarmedical image corresponding to the second distribution information isenlarged and displayed within the corresponding display frame withrespect to, as a center of enlargement, the corresponding region ofinterest included in the similar medical image corresponding to thesecond distribution information; and in response to detection that thethird distribution information has been selected, display a similarmedical image corresponding to the third distribution information in acorresponding display frame among the display frames in such a mannerthat the similar medical image corresponding to the third distributioninformation is enlarged and displayed within the corresponding displayframe with respect to, as a center of enlargement, the correspondingregion of interest included in the similar medical image correspondingto the third distribution information and in such a manner that thecorresponding region of interest includes the pleura.

According to this aspect, when similar medical images are classifiedaccording to the distribution type of the corresponding region ofinterest, the similar medical images are displayed in accordance withthe distribution type. This may enable an operator to classify thesimilar medical images in accordance with the distribution type of thecorresponding region of interest without performing further operationssuch as enlarging the similar medical images in accordance with thedistribution type or centering the corresponding region of interest.Accordingly, a complicated process in which, even after classificationaccording to the distribution type of the corresponding region ofinterest is completed, similar operations are repeatedly performed oneach of a large number of classified similar medical images may besignificantly reduced. This may result in a significant reduction in therisk of physician's thoughts or physician's concentration on medicaltreatment decision being interrupted by such a complicated process,helping the physician maintain their thoughts or concentration on makingtheir medical treatment decision. The accuracy of medical treatmentdecision may thus be improved.

In addition, in the aspect described above, for example, the firstdistribution information may be information indicating a distributionthat belongs to a bilateral category, a multiple category, a diffusecategory, or a hematogenous category. The second distributioninformation may be information indicating a distribution that belongs toa segmental category or a bronchial category. The third distributioninformation may be information indicating a distribution that belongs toa subpleural category.

According to this aspect, for a distribution that belongs to thebilateral, multiple, diffuse, or hematogenous category, similar medicalimages are displayed with the initial display size. For a distributionthat belongs to the segmental or bronchial category, similar medicalimages are enlarged and displayed. For a distribution that belongs tothe subpleural category, similar medical images are enlarged anddisplayed in such a manner that the pleura is included.

For a distribution that belongs to the bilateral, multiple, diffuse, orhematogenous category, a lesion may occupy the entire lung or a lesionmay occupy a large area of the lung. Thus, there is a need, based on themedical knowledge, that a similar medical image be displayed with theinitial display size or without enlargement of the similar medicalimage.

For a distribution that belongs to the segmental or bronchial category,in contrast, the above possibility is less likely to occur. Thus,enlarging and displaying similar medical images by selecting adistribution that belongs to the segmental or bronchial category mayremove the step of enlarging and displaying similar medical images,preventing the physician's concentration from being interrupted. For adistribution that belongs to the subpleural category, the positionalrelationship between the pleura and the lesion is an important index fordiagnosis. Thus, there is a need, based on the medical knowledge, that asimilar medical image be enlarged and displayed in such a manner that apleura is included.

An aspect of the present disclosure provides a control method includingdisplaying a first resulting image, obtained by enlarging an imageincluded in a first area, in a first display area of a display deviceinstead of displaying a first image in the first display area, the firstimage including the first area and a third area, the first areaincluding a second area; displaying a second resulting image, obtainedby enlarging an image included in a fourth area, in a second displayarea of the display device instead of displaying a second image in thesecond display area, the second image including the fourth area and asixth area, the fourth area including a fifth area; and displaying afourth resulting image, obtained by enlarging an image included in thesixth area, in the second display area instead of displaying the secondresulting image in the second display area, in response to receipt of aninstruction for displaying a third resulting image, obtained byenlarging an image included in the third area, in the first display areainstead of displaying the first resulting image in the first displayarea. A ratio of L1/L2 is proportional to a ratio of S2/S1, where L1represents a distance between a center of the first area and a center ofthe third area, L2 represents a distance between a center of the fourtharea and a center of the sixth area, S1 represents an area of the secondarea, and S2 represents an area of the fifth area.

First Embodiment

An embodiment of the present disclosure will now be describedhereinafter with reference to the drawings. In the drawings, the same orsimilar components are represented by the same numerals.

FIG. 1 is an overall configuration diagram of a hospital informationsystem in which an information terminal according to this embodiment isused. As illustrated in FIG. 1, the hospital information system includesan information terminal 100, a medical information management system200, and a case search system 300.

The information terminal 100, the medical information management system200, and the case search system 300 are connected to one another via anetwork 400 so as to be capable of communicating with one another.

The medical information management system 200 and the case search system300 may not necessarily be located in the hospital, and may beimplemented by software operating on a data center, a private cloudserver, a public cloud server, or the like located outside the hospital.In a case where the medical information management system 200 and thecase search system 300 are located in the hospital, the network 400 maybe a local area network (LAN). Examples of a LAN include wired LANsspecified by the Institute of Electrical and Electronics Engineers(IEEE) 802.3 series standards, wireless LANs specified by the IEEE802.11 series standards, and networks including both such wired andwireless LANs. In a case where the medical information management system200 and the case search system 300 are implemented by using a serverlocated outside the hospital, the network 400 may be the Internet.

The information terminal 100 may be a personal computer or aninformation terminal such as a tablet terminal. The medical informationmanagement system 200 may be a picture archiving and communicationsystem (PACS), an electronic medical record system, or the like.

FIG. 2 is a block diagram illustrating the configuration of theinformation terminal 100, the medical information management system 200,and the case search system 300. As illustrated in FIG. 2, theinformation terminal 100 includes a display 101, an operation unit 102,an input control unit 103, a display control unit 104, a region ofinterest (ROI) management unit 105, a display box management unit 106, adisease list management unit 108, a distribution list management unit109, a communication control unit 110, a box layout management unit 111,and an enlarged image generation unit 112.

The display 101 may be, for example, a liquid crystal monitor. Thedisplay 101 displays a medical chart image and a medical image to beused for diagnosis, and also displays a report entry image or the likein which the results of diagnosis are entered. While image-baseddiagnosis requires at least one display 101, two to three displays 101are typically used for image-based diagnosis. In this embodiment, twodisplays 101 are used, one of which is a display 101 a, and the other ofwhich is a display 101 b (see FIG. 3).

FIG. 3 illustrates external views of the two displays 101 a and 101 b.In FIG. 3, four medical image viewers arranged in two rows and twocolumns are displayed on the display 101 a, and a screen for the casesearch system 300 is displayed on the display 101 b. In a case where asingle display 101 is used, the two display screens are displayed inseparate areas on the display screen of the single display 101.

The operation unit 102 includes, for example, a keyboard and a mouse,and accepts a variety of operations input by a user on the informationterminal 100. For example, the operation unit 102 accepts operationssuch as an operation performed by the user on a medical image or medicalchart image displayed on the display 101, and an operation for enteringthe results of diagnosis in a report input screen.

Upon detection of a user's operation on the operation unit 102, theinput control unit 103 interprets the operation, and notifies the othercomponents of the content of the operation. For example, the inputcontrol unit 103 detects the position of the mouse pointer on thedisplay 101 by using coordinate data output from the mouse serving asthe operation unit 102, and causes the mouse pointer to be displayed onthe display 101. If a graphical user interface (GUI) component (e.g., aGUI button) generated by the display control unit 104 is displayed atthe display position of the mouse pointer when a click of the mouse isdetected, the input control unit 103 determines that the user hasselected the GUI component, and notifies the other components that theGUI component has been selected by the user.

The display control unit 104 generates a GUI of the information terminal100, and displays the GUI on the display 101.

The ROI management unit 105 generates region-of-interest informationindicating a region of interest (ROI) set on a search query imagedescribed below for a similar case search, and stores theregion-of-interest information in a memory to manage theregion-of-interest information.

The display box management unit 106 stores display box managementinformation 4410 described below (FIG. 40) in the memory to manage thedisplay box management information 4410.

The disease list management unit 108 generates a disease list (FIG. 46)that is a list of diseases corresponding to similar cases displayed in acase display area 710 (FIG. 6), and stores the disease list in thememory to manage the disease list.

The distribution list management unit 109 generates a distribution list(FIG. 51) that is a list of distributions of lesions of the similarcases displayed in the case display area 710, and stores thedistribution list in the memory to manage the distribution list.

The communication control unit 110 includes, for example, acommunication device for connecting the information terminal 100 to thenetwork 400, and controls communication between the information terminal100 and the medical information management system 200 and communicationbetween the information terminal 100 and the case search system 300.Further, the communication control unit 110 accepts from other blocks arequest for transmitting a variety of types of data, and transmits datato the medical information management system 200 or the case searchsystem 300. In addition, the communication control unit 110 receivesdata transmitted from the medical information management system 200 orthe case search system 300, and passes the data to the correspondingblock.

The box layout management unit 111 generates layout managementinformation 4200 described below (FIG. 43), and stores the generatedlayout management information 4200 in a memory to manage the layoutmanagement information 4200.

The enlarged image generation unit 112 generates an enlarged image of athumbnail image of a similar case. The enlarged image generation unit112 acquires the amount of operation performed on the operation unit 102by the user from the input control unit 103. The enlarged imagegeneration unit 112 receives, through the communication control unit110, similar case data (including similarity and region-of-interestinformation) transmitted from the case search system 300.

The enlarged image generation unit 112 calculates enlargement factorsfor individual thumbnail images of similar cases displayed in the casedisplay area 710 among a number of similar cases (e.g., NC similarcases) obtained as a result of the similar case search, and generates anumber of enlarged images equal to the number of thumbnail imagesdisplayed.

As illustrated in FIG. 2, the medical information management system 200includes a patient information accumulation unit 201, a patientinformation management unit 202, a medical image data accumulation unit203, a medical image data management unit 204, a diagnostic reportmanagement unit 205, and a communication control unit 206.

The patient information accumulation unit 201 accumulates patientinformation 1000 (FIG. 29) in which personal information such as thegender and age of a patient, clinical information such as the pastmedical history that the patient has, and test information on medicaltests that the patient has undergone, such as a blood test, areregistered.

The patient information management unit 202 performs processes, such asa process for registering data input by a user in the patientinformation 1000 (FIG. 29) accumulated in the patient informationaccumulation unit 201 to update the patient information 1000, and aprocess for outputting the patient information 1000 to the displaycontrol unit 104, to manage the patient information 1000. The medicalimage data accumulation unit 203 accumulates medical image datarepresenting test images of the patient.

The medical image data management unit 204 stores the medical image datain the medical image data accumulation unit 203 to manage the medicalimage data.

The diagnostic report management unit 205 manages a diagnostic report3000 (FIG. 32) which shows the results of the diagnosis made by thephysician based on the results of tests given to the patient.

The communication control unit 206 includes, for example, acommunication device for connecting the medical information managementsystem 200 to the network 400. The communication control unit 206accepts from other blocks a request for transmitting a variety of typesof data, and transmits data to the information terminal 100 or the casesearch system 300. In addition, the communication control unit 206receives data transmitted from the information terminal 100 or the casesearch system 300, and passes the data to the corresponding block.

As illustrated in FIG. 2, the case search system 300 includes a similarcase data accumulation unit 301, an image feature extraction unit 302,and a similar case search unit 303, and a communication control unit304.

The similar case data accumulation unit 301 accumulates, in advance,similar case data 4000 (FIG. 33) in which image features extracted froma large number of similar cases selected as target data for a similarcase search from among the similar cases managed in the medicalinformation management system 200, generated thumbnail images, and thelike are registered.

The image feature extraction unit 302 extracts an image feature inregion-of-interest information on the search query image transmittedfrom the communication control unit 110 of the information terminal 100.The region-of-interest information is an example of first designationinformation indicating a region of interest.

The similar case search unit 303 compares the image feature extracted bythe image feature extraction unit 302 with each of image features in oneor more similar cases accumulated in the similar case data accumulationunit 301, and generates similar case search results.

The communication control unit 304 includes, for example, acommunication device for connecting the case search system 300 to thenetwork 400. The communication control unit 304 accepts from otherblocks a request for transmitting a variety of types of data, andtransmits data to the information terminal 100 or the medicalinformation management system 200. In addition, the communicationcontrol unit 304 receives data transmitted from the information terminal100 or the medical information management system 200, and passes thedata to the corresponding block.

FIG. 4 is a diagram illustrating an example configuration of animplementation of the information terminal 100. As illustrated in FIG.4, the information terminal 100 includes an application 501, anoperating system (OS) 502, a memory 503, and other hardware (notillustrated).

The application 501 is application software for causing a personalcomputer or a tablet terminal to function as the information terminal100, and is executed by a processor of the information terminal 100. Theinformation terminal 100 may implement the application 501 by readingthe application 501 from a computer-readable recording medium, or mayimplement the application 501 by downloading the application 501 from anetwork.

The application 501 includes a medical information managementapplication and a similar case search application. The medicalinformation management application is an application for allowing theinformation terminal 100 to operate in coordination with the medicalinformation management system 200, and the similar case searchapplication is an application for allowing the information terminal 100to operate in coordination with the case search system 300. The medicalinformation management application and the similar case searchapplication transmit and receive data to and from each other so thatservices provided by the medical information management system 200 andthe case search system 300 are integrated in the information terminal100.

The OS 502 is basic software of the information terminal 100, and isexecuted by a processor of the information terminal 100. The memory 503includes storage devices such as a random access memory (RAM) and aread-only memory (ROM), which are included in the information terminal100, and stores data sets included in the application 501.

The processor of the information terminal 100 executes the application501 to implement the functions of the input control unit 103, thedisplay control unit 104, the ROI management unit 105, the display boxmanagement unit 106, the disease list management unit 108, thedistribution list management unit 109, the communication control unit110, the box layout management unit 111, and the enlarged imagegeneration unit 112, which are illustrated in FIG. 2.

In this embodiment, the information terminal 100 may be implementedsolely by the application 501, or may be implemented by the application501 and the OS 502. Alternatively, the information terminal 100 may beimplemented by the application 501, the OS 502, and the memory 503, ormay be implemented by the application 501, the OS 502, the memory 503,and any other hardware (not illustrated). The information terminal 100according to this embodiment is achievable through any of theimplementations described above.

FIG. 5 is a diagram illustrating an example of a basic screen K1displayed on the display 101 a immediately after the similar case searchapplication is started on the information terminal 100. The basic screenK1 illustrated in FIG. 5 includes four medical image viewers 610 to 640.Typical medical images are recorded in Digital Imaging and Communicationin Medicine (DICOM) format, and the medical image viewers 610 to 640 areDICOM-compatible viewers. The medical images as used in this embodimentare chest CT images constituted by a large number of tomographic images(hereinafter referred to as “slice images”) in DICOM format. This ismerely an example, and CT images of any other body part (e.g., the head,abdomen, legs, or arms) may be used.

Each of the chest CT images displayed in the medical image viewers 610to 640 is switched from one slice image to another through an operationwith the mouse or keyboard. The slice images constituting the chest CTimages are arranged in order from, for example, the neck toward theabdomen.

For example, when the input control unit 103 detects a rotation of themouse wheel while the mouse pointer is on the medical image viewer 610,the display control unit 104 switches the slice image currentlydisplayed in the medical image viewer 610 in accordance with the amountof rotation which is detected. For example, when the mouse wheel isrotated rearward (or toward the user of the mouse) by an amountcorresponding to one click while the mouse is in the medical imageviewer 610, the display control unit 104 switches the currentlydisplayed slice image to the slice image corresponding to the next sliceposition. For example, when the mouse wheel is rotated forward (or awayfrom the user of the mouse) by an amount corresponding to one clickwhile the mouse is in the medical image viewer 610, the display controlunit 104 switches the currently displayed slice image to the slice imagecorresponding to the preceding slice position. Accordingly, the user,such as a physician, retrieves the desired slice image while rotatingthe mouse wheel forward or rearward to appropriately switch betweenslice images to be displayed in the medical image viewer 610.

In place of chest CT images, magnetic resonance imaging (MRI) images orsimple X-ray images may be used as medical images. Furthermore, fourmedical image viewers are used in the example illustrated in FIG. 5.This is merely an example, and a different number of medical imageviewers, such as six or eight medical image viewers, may be used. As thenumber of medical image viewers used increases, the number of images tobe simultaneously compared also increases whilst the display area perimage decreases. Accordingly, the number of medical image viewers may bemade variable, as desired, in accordance with the display size of thedisplay 101 a. By way of example, the number of medical image viewersmay be changed by the user or an administrator as desired.

Before the similar case search application is started, a slice image ofa chest CT image of a certain patient is displayed in the entire area ofthe display 101 a. When the similar case search application is startedby the user such as a radiologist in this situation, the slice imagebeing displayed in the entire area of the display 101 a is displayed inthe medical image viewer 610.

That is, a search query image being displayed in the entire area of thedisplay 101 a when the user starts the similar case search applicationis initially displayed in the medical image viewer 610. The displaycontrol unit 104 may superimpose the region of interest (ROI) of thetarget to be subjected to a similar case search on a search query imagefor display. The search query image is an example of a target medicalimage that is a medical image to be interpreted.

In FIG. 5, no images are displayed in the medical image viewers 620 to640. If there are a plurality of test images of a patient to bediagnosed and a plurality of test images are displayed on the display101 a before the similar case search application is started, the displaycontrol unit 104 may directly display the plurality of test images inthe medical image viewers 620 to 640.

FIG. 6 is a diagram illustrating an example of a basic screen K2displayed on the display 101 b immediately after the similar case searchapplication is started on the information terminal 100. The basic screenK2 illustrated in FIG. 6 includes a case display area 710, a layout area720, a disease list display area 730, and a distribution list displayarea 750. The layout area 720 is an example of a first display area, andthe case display area 710 is an example of a second display area.

The case display area 710 is an area where thumbnail images of similarcases that are similar to the search query image are displayed in orderof similarity. A thumbnail image of a similar case is an example of asimilar medical image.

Since the case display area 710 shows a large number of similar cases,further processing for resolution conversion or pixel-value conversionwill take time. To avoid this inconvenience, the thumbnail images arecreated in advance from the original slice images, and are stored in thecase search system 300.

Further description will now be given of resolution conversion andpixel-value conversion. Each original slice image has a resolution of512 pixels by 512 pixels, whereas each thumbnail image has a lowerresolution. Thus, resolution conversion is needed. Each of the thumbnailimages is generated through the resolution reduction and grayscaleconversion of the corresponding one of the original slice images.

For example, a grayscale conversion process is performed in thefollowing way. The slice images obtained by CT imaging have pixel values(CT values) of 2000 grayscale values from −1000 to +1000 (expressed inHounsfield units (HU)), and will not be directly displayed on a standard8-bit grayscale display. Even if such slice images can be displayed, itis difficult for a person to distinguish the areas of pulmonaryemphysema (with a CT value of −1000 HU), normal lung tissue (with a CTvalue of approximately −900 HU), the area of ground-glass opacity (witha CT value of −800 HU), soft tissue (with a CT value of −100 to −50 HU),water (with a CT value of 0 HU), and bone (with a CT value of 1000 HU),in the range of the 2000 grayscale values, from one another with thenaked eye.

Thus, slice images are typically reconstructed with 8-bit pixel valuesfor display on a display, where a window level and a window width areset for each pixel value. The window level represents the CT value ofthe center of the window, and the window width represents the differencebetween the upper limit and lower limit of a range centered about thecenter of the window.

For example, in a case where a DICOM image is reconstructed with thepulmonary condition, the window level is set to −550 to −800 and thewindow width is set to 1000 to 1600. Thus, a thumbnail image is alsogenerated through the processing described above to reduce the pixelvalues of the original slice image to 8-bit pixel values.

The thumbnail images displayed in the case display area 710 arethumbnail images representing similar cases for which the distance fromthe feature vector of the case to be diagnosed is less than or equal toa predetermined threshold value. The distance is a Euclidean distance,by way of example. Any other distance measure, such as city block, maybe used as the distance. As the distance between the two images to becompared decreases, the similarity between them increases. The featurevectors are not obtained from the thumbnail images but are obtained fromthe original images, that is, the DICOM images.

FIG. 7 is a diagram illustrating a display area 701 (an example of adisplay frame) for a certain similar case extracted from among thesimilar cases displayed in the case display area 710. A thumbnail imageis displayed in the display area 701 for the similar case, and adefinitely diagnosed disease display area 711 and a distance displayarea 712 are placed below the thumbnail image. The definitely diagnoseddisease display area 711 shows the name of the definitely diagnoseddisease of the target similar case. The name of the definitely diagnoseddisease is the name of a disease as which the target similar case hasbeen diagnosed in definite diagnosis. The distance display area 712shows the distance between the feature vector for the slice image of thetarget similar case and the feature vector for the search query image.In the example illustrated in FIG. 7, the definitely diagnosed diseasedisplay area 711 shows “nontuberculous mycobacteria (NTM)”. Thus, theillustrated thumbnail image is a thumbnail image of a similar casediagnosed as “nontuberculous mycobacteria (NTM)” in definite diagnosis.The distance display area 712 shows “0.05”, which indicates that thedistance between the slice image of the similar case and the searchquery image is “0.05”.

As illustrated in FIG. 7, the thumbnail image of the similar case, whichis displayed in the display area 701, includes a corresponding region ofinterest CROI. The corresponding region of interest CROI is a regioncorresponding to the region of interest set on the search query image(i.e., the medical image to be interpreted) (that is, the correspondingregion of interest CROI is a region similar to the region of interest).In the following, the corresponding region of interest is also referredto simply as the “region of interest”.

Referring back to FIG. 6, for example, a number-of-search-result displayarea 713 is placed in an upper left portion of the basic screen K2. Thenumber-of-search-result display area 713 shows the number of similarcases similar to the case to be diagnosed. The number of similar casesis obtained from the case search system 300 as a result of the search.

If the number of similar cases is very large, it will be difficult todisplay all the similar cases in the case display area 710 at the sametime. Accordingly, the case display area 710 has, in a right portionthereof, for example, a vertical scrollbar 715. The display control unit104 provides vertical scrolling through the thumbnail images displayedin the case display area 710 in accordance with the amount of movementof the scrollbar 715. This enables the user to display currentlyinvisible similar cases in the case display area 710 so that the usercan observe the similar cases.

The scrollbar 715 may be a horizontal scrollbar. In this case, thedisplay control unit 104 may be configured to provide horizontalscrolling through the thumbnail images displayed in the case displayarea 710 in accordance with the amount of movement of the scrollbar 715.

The information terminal 100 is configured to acquire from the casesearch system 300 thumbnail images for which the distance from thesearch query image is less than or equal to a predetermined thresholdvalue. This is merely an example. For example, the information terminal100 may always acquire a certain number of thumbnail images from thecase search system 300 in order of decreasing similarity. Alternatively,the information terminal 100 may acquire thumbnail images from the casesearch system 300 so that a certain number of thumbnail images of acertain definitely diagnosed disease are always included.

The thumbnail images may be displayed in the case display area 710 insuch a manner that, for example, the thumbnail image with the shortestdistance from the search query image is displayed at the left end of thetop row and the distance sequentially increases from left to right,where, once the right end of the same row is reached, the next,large-distance thumbnail image is displayed at the left end of thesecond row from the top. That is, the following display technique may beused: The thumbnail images are displayed in the case display area 710,from left to right, top to bottom, in order of increasing distance.

Other display technique may be used in this embodiment. For example, thethumbnail images may be displayed in such a manner that the thumbnailimage with the shortest distance is displayed at top end of the firstcolumn from the left and the distance sequentially increases from top tobottom, where, once the bottom end of the same column is reached, thenext, large-distance thumbnail image is displayed at the top end of thesecond column from the left. Alternatively, the plurality of displaytechniques described above may be switched between by the user.

In the example described above, distance is used as similarity measure.Any index indicating the similarity between images, such as cosinesimilarity, may be used. In a case where cosine similarity is used, asthe value approaches 1, the similarity between two images to be comparedincreases.

The similar cases to be displayed in the case display area 710 can berefined by a disease name, e.g., a disease name displayed in the diseaselist display area 730, or by a distribution of lesions, e.g., adistribution of lesions displayed in the distribution list display area750, which will be described in detail below. A condition under whichthe similar cases are refined in the current setting is displayed in adisplay condition display area 714. The example illustrated in FIG. 6illustrates the state immediately after a similar case search has beenperformed, and no refinement is performed. Thus, “all diseases anddisorders” is displayed in the display condition display area 714.

The thumbnail images of the similar cases, which are displayed in thecase display area 710, are designed to be able to be enlarged by a useroperation. The enlarged display of the thumbnail images of the similarcases will be described hereinbelow.

FIG. 8 is a diagram illustrating the basic screen K2, which is obtainedwhen one of the thumbnail images displayed in the case display area 710is selected. As illustrated in FIG. 8, in each display area, a thumbnailimage is displayed in its entirety in the state where the basic screenK2, which is obtained immediately after the similar case search is made,is being displayed. The case display area 710 includes a predeterminednumber ND (in this embodiment, ND=20) of display areas each showing athumbnail image.

The input control unit 103 of the information terminal 100 constantlymonitors the input through the operation unit 102 such as the mouse. Theinput control unit 103 detects that the operation of clicking the mousehas been input by the user and that one of the thumbnail images of thesimilar cases displayed in the case display area 710 has been selectedin accordance with the operation. Then, the display control unit 104changes the color of the background of the selected thumbnail image.

In the example illustrated in FIG. 8, a thumbnail image of a similarcase displayed in a display area 1301 in the first row and the fourthcolumn is selected in the case display area 710. Accordingly, the colorof the background against which the thumbnail image is displayed in thedisplay area 1301 is changed. Specifically, the color of a frame areasurrounding the selected thumbnail image is changed. This enables theuser to be notified that the associated thumbnail image has beenselected.

The color of the background is, for example, a color that is clearlydistinguishable from the color of the background of the case displayarea 710. In the example illustrated in FIG. 8, yellow is used by way ofexample. The example illustrated in FIG. 8 provides an embodiment inwhich the color of the frame area of the thumbnail image is changed. Inan alternative embodiment, the method of blinking or illuminating theframe area may be used.

As illustrated in FIG. 8, when the user performs an enlargementoperation by, for example, rotating the mouse wheel while one thumbnailimage is selected, the input control unit 103 detects the amount ofrotation of the mouse wheel, and notifies the enlarged image generationunit 112 of the detected amount of rotation. Then, the enlarged imagegeneration unit 112 individually determines enlargement factors for therespective thumbnail images by, for example, using the notified amountof rotation, and enlarges all the thumbnail images with the determinedenlargement factors. As illustrated in FIG. 9 or FIG. 10, for example,the display control unit 104 displays the thumbnail images enlarged bythe enlarged image generation unit 112 in the case display area 710.

FIG. 9 is a diagram illustrating the basic screen K2, which is obtainedwhen all the thumbnail images displayed in the case display area 710 areenlarged. As illustrated in FIG. 9, the 20 thumbnail images displayed inthe case display area 710 have been enlarged. This may significantlyreduce the processing load on the information terminal 100, compared tothe case where the thumbnail images of all the 62 pieces of similar casedata received from the case search system 300 are enlarged.

FIG. 10 is a diagram illustrating the basic screen K2, which is obtainedwhen all the thumbnail images displayed in the case display area 710 areenlarged and which is different from that illustrated in FIG. 9. In FIG.10, the enlarged image generation unit 112 generates enlarged thumbnailimages so that the size of the corresponding region of interest CROI ineach of the enlarged thumbnail images is the same as the size of thecorresponding one of the display areas.

When enlarging a currently displayed thumbnail image, the enlarged imagegeneration unit 112 generates an enlarged image so that, as illustratedin FIG. 9 or FIG. 10, the position of the center of the correspondingregion of interest CROI matches the position of the center of thedisplay area 1301. When enlarging a thumbnail image, furthermore, asillustrated in FIG. 9 or FIG. 10, the display control unit 104 maintainsthe size of the display area 1301 as is without increasing the size ofthe display area 1301.

Further, the enlarged image generation unit 112 may set an enlargementfactor for each thumbnail image to a different value. This enables thethumbnail images to be enlarged so that, as illustrated in FIG. 9 orFIG. 10, the corresponding regions of interest CROI of the thumbnailimages, when enlarged, have the same size.

In the way described above, a physician who makes image-based diagnosismerely performs an enlargement operation on one thumbnail image of asimilar case on which they focus their attention, thus allowing thethumbnail images of all the other similar cases being displayed, as wellas the thumbnail image of the similar case, to be enlarged anddisplayed. Thus, the physician is able to compare a plurality of similarcases in detail by issuing instructions once. Accordingly, the number ofoperations may be significantly reduced.

In FIG. 8, the thumbnail image of the similar case displayed in thedisplay area 1301 in the first row and the fourth column is selected.The user can select any thumbnail image. The user may only be requiredto select any one of the 20 thumbnail images being displayed.

FIG. 11 is a diagram illustrating the basic screen K2, which is obtainedwhen a thumbnail image different from that illustrated in FIG. 8 isselected from among the thumbnail images displayed in the case displayarea 710. In FIG. 11, the thumbnail image displayed in a display area801 in the second row and the fourth column is selected by a user. Alsoin FIG. 11, when the user performs an enlargement operation by, forexample, rotating the mouse wheel while the thumbnail image in thesecond row and the fourth column is selected, the input control unit 103detects the amount of rotation of the mouse wheel, and notifies theenlarged image generation unit 112 of the detected amount of rotation.Then, the enlarged image generation unit 112 individually determinesenlargement factors for the respective thumbnail images by, for example,using the notified amount of rotation, and enlarges all the thumbnailimages with the determined enlargement factors. The display control unit104 displays the thumbnail images enlarged by the enlarged imagegeneration unit 112 in the case display area 710.

In the foregoing description, a user performs an enlargement operationby rotating the mouse wheel. However, the present disclosure is notlimited to this. The user may perform an enlargement operation by, forexample, placing the mouse pointer on one of the thumbnail imagesdisplayed in the case display area 710 and pressing, for example, the uparrow key or down arrow key on the keyboard while pressing the mousebutton. In this case, the input control unit 103 may count the length oftime during which the up arrow key or down arrow key is pressed. Theenlarged image generation unit 112 may determine an enlargement factorby using, for example, the length of time during which the up arrow keyor down arrow key is pressed.

The details of a specific processing procedure for enlarging a thumbnailimage will be described below.

The thumbnail images displayed in the case display area 710 are designedso that the display areas in the thumbnail images can be changed by auser operation. In the following, a change of a display area of athumbnail image of a similar case will be described.

FIG. 12 is a diagram illustrating the basic screen K2, which is obtainedwhen one of the thumbnail images displayed in the case display area 710is selected after the thumbnail images are enlarged and displayed. Asillustrated in FIG. 12, while the basic screen K2, which is obtainedafter the thumbnail images are enlarged and displayed, is beingdisplayed, the thumbnail images are enlarged and displayed in therespective display areas.

The input control unit 103 of the information terminal 100 constantlymonitors the input through the operation unit 102 such as the mouse. Theinput control unit 103 detects that the operation of clicking the mousehas been input by the user and that one of the thumbnail images of thesimilar cases displayed in the case display area 710 has been selectedin accordance with the operation. Then, the display control unit 104changes the color of the background of the selected thumbnail image.

In the example illustrated in FIG. 12, the thumbnail image of thesimilar case displayed in a display area 1201 in the second row and thefourth column is selected in the case display area 710. Accordingly, thecolor of the background against which the thumbnail image is displayedin the display area 1201 is changed. Specifically, the color of a framearea surrounding the selected thumbnail image is changed. This enablesthe user to be notified that the associated thumbnail image has beenselected.

The color of the background is, for example, a color that is clearlydistinguishable from the color of the background of the case displayarea 710. In the example illustrated in FIG. 12, yellow is used by wayof example. The example illustrated in FIG. 12 provides an embodiment inwhich the color of the frame area of the thumbnail image is changed. Inan alternative embodiment, the method of blinking or illuminating theframe area may be used.

As illustrated in FIG. 12, the user performs a (drag) operation ofchanging the mouse position while, for example, pressing the left buttonof the mouse while one of the thumbnail images is selected.

FIG. 13 is a diagram schematically illustrating a drag operation 1202performed by a user while the basic screen K2 is being displayed. Whenthe user performs the drag operation 1202, the input control unit 103detects the amount of movement of the mouse, and notifies the enlargedimage generation unit 112 of the detected amount of movement. Then, theenlarged image generation unit 112 determines an amount of movement of adisplay area in a thumbnail image by using the detected amount ofmovement of the mouse, and generates a thumbnail image in which thedisplay area has moved by the determined amount. The display controlunit 104 displays, in the case display area 710, thumbnail images thathave been caused to move by the enlarged image generation unit 112.

FIG. 14 is a diagram illustrating the basic screen K2, which is obtainedwhen a display area of a thumbnail image displayed in the case displayarea 710 is caused to move. Specifically, in FIG. 14, not only thedisplay area of the selected thumbnail image but also the display areasof the 20 thumbnail images in total which are displayed in the casedisplay area 710 are caused to move.

When causing the display areas of the currently displayed thumbnailimages to move, the enlarged image generation unit 112 generatesthumbnail images after movement so that, as illustrated in FIG. 14, thepositions of the corresponding regions of interest CROI in all thethumbnail images displayed in the case display area 710 are moved in therespective display areas 1201 by the same amount. Specifically, forexample, the user drags the mouse to the left, causing the display areasof the 20 thumbnail images in total, which are displayed in enlargedform, to move so that the portion to the right of the correspondingregion of interest CROI in each of the 20 thumbnail images appears.

FIG. 15 is a diagram schematically illustrating a drag operation 1501performed by a user while the basic screen K2 is being displayed in themanner illustrated in FIG. 14. As illustrated in FIG. 15, when the userperforms an operation of changing the mouse position while furtherpressing the left button of the mouse from the state illustrated in FIG.14, the input control unit 103 detects the amount of movement of themouse, and notifies the enlarged image generation unit 112 of thedetected amount of movement. Then, the enlarged image generation unit112 determines an amount of movement of a display area in a thumbnailimage by using the detected amount of movement of the mouse, andgenerates a thumbnail image in which the display area has moved thedetermined amount. The display control unit 104 displays, in the casedisplay area 710, thumbnail images that have been caused to move by theenlarged image generation unit 112.

FIG. 16 is a diagram illustrating the basic screen K2, which is obtainedwhen a display area in a thumbnail image displayed in the case displayarea 710 moves with the drag operation 1501 illustrated in FIG. 15.Specifically, as in FIG. 14, in FIG. 16, not only the display area inthe selected thumbnail image but also the display areas in the 20thumbnail images in total which are displayed in the case display area710 have moved. Also in FIG. 16, when causing the display areas of thecurrently displayed thumbnail images to move, the enlarged imagegeneration unit 112 generates thumbnail images after movement so thatthe positions of the corresponding regions of interest CROI in all thethumbnail images displayed in the case display area 710 are moved in therespective display areas by the same amount. Specifically, the userdrags the mouse to the left, causing the display areas in the 20thumbnail images in total, which are displayed in enlarged form, to moveso that the portion to the right of the corresponding regions ofinterest CROI in each of the 20 thumbnail images appears. The details ofthe process for causing a display area in a thumbnail image to move willbe described below.

For example, in pulmonary adenocarcinoma, pulmonary tuberculosis, andthe like, in the process of separating a cancer cell or bacteria fromthe primary lesion, such a cancer cell or bacteria may be inhaled intoother parts, and disseminated lesions in the bronchiole may be observed.Thus, a physician observes not only a primary lesion but also secondarylesions around the primary lesion in image-based diagnosis.

In a similar case search, there is a need for a physician to, afterdetermining that the primary lesion in the similar case under diagnosisis similar to the case to be used for image interpretation, determinewhether or not secondary lesions around the primary lesion are alsosimilar to refine similar cases obtained as a result of the search tonarrow down the selection of disease names. To meet the need, a functionof enabling a user to observe not only the primary lesion to which thecorresponding region of interest is assigned in a thumbnail image of asimilar case but also a region surrounding the primary lesion by causingthe display area to move in response to an operation performed by theuser may be effective for image-based diagnosis. In particular, in orderto distinguish a plurality of diseases having similar primary lesions,the user compares secondary lesions around the primary lesions. It isthus preferable that the user be able to compare surrounding regions ina plurality of similar cases at the same time.

With the function described above, a physician who makes image-baseddiagnosis merely operates a display area of a thumbnail image of asimilar case on which they focus their attention, thus allowing thedisplay areas for the similar cases other than the similar case on whichthey focus their attention to move synchronously with the display areafor the focused similar case. Thus, the physician is able to comparesimilar cases in detail by issuing instructions once. Accordingly, thenumber of operations may be significantly reduced.

As illustrated in FIG. 14 and FIG. 16, the enlarged image generationunit 112 generates thumbnail images after movement so that the positionsof the corresponding regions of interest CROI in all the thumbnailimages displayed in the case display area 710 are moved in therespective display areas 1201 by the same amount. Note that the area ofthe corresponding region of interest CROI included in the similarmedical image selected by the user (in the examples illustrated in FIG.12 to FIG. 16, the thumbnail image displayed in the display area 1201 inthe second row and the fourth column) may not necessarily be the same asthe area of the corresponding regions of interest CROI included in theother similar medical images.

Accordingly, a value obtained by multiplying the amount of operationinput by the user by the enlargement factor for each thumbnail image isused as the amount of movement of the associated display area. Forexample, it is assumed that the area of the corresponding region ofinterest CROI included in the similar medical image selected by the user(an example of a selected similar medical image) is larger than the areaof the corresponding region of interest CROI included in another similarmedical image (an example of an unselected similar medical image). Inthis case, if the movement distance of the similar medical imageselected by the user is the same as the movement distance of the othersimilar medical image, as a result of movement of the other similarmedical image, the corresponding region of interest CROI included in theother similar medical image moves a large amount. Consequently, a largernumber of surrounding areas away from the corresponding region ofinterest CROI in the other similar medical image appear. In general,secondary lesions are more likely to be present in surrounding areasclose to the corresponding region of interest CROI in the other similarmedical image.

For this reason, if, as a result of movement of another similar medicalimage other than a selected similar medical image, a surrounding areaaway from the corresponding region of interest CROI in the other similarmedical image appears, secondary lesions may fail to be detected. Toavoid such a risk, as illustrated in FIG. 14 and FIG. 16, the displayareas of the thumbnail images are caused to move so that enlargedthumbnail images which are displayed in the case display area 710 seemto move the same amount in the respective display areas 1201.Accordingly, for example, even if the area of the corresponding regionof interest CROI included in a similar medical image selected by theuser is larger than the area of the corresponding region of interestCROI included in another similar medical image, the movement distance ofthe similar medical image selected by the user is not equal to themovement distance of the other similar medical image. This may prevent asurrounding area away from the corresponding region of interest CROIincluded in the other similar medical image from appearing as a resultof movement of the other similar medical image.

Consequently, it may be possible to reduce the risk of secondary lesionsfailing to be detected without the need for the operation to cause aplurality of similar medical images to separately move, making thephysician concentrate their attention on the medical treatment decision.Accordingly, the accuracy of medical treatment decision may beeffectively improved.

Referring back to FIG. 6, the layout area 720 is displayed in, forexample, a lower left portion of the basic screen K2 illustrated in FIG.6. The layout area 720 is used so that an image that the user wishes toobserve in more detail among the thumbnail images of the similar casesdisplayed in the case display area 710 is displayed in a medical imageviewer on the display 101 a. As illustrated in FIG. 5, the four medicalimage viewers 610 to 640 arranged in two rows and two columns aredisplayed on the display 101 a. Further, the layout area 720 has fourdisplay boxes 721 to 724 arranged in two rows and two columns. In themanner described above, the number and layout of the medical imageviewers 610 to 640 displayed on the display 101 a is consistent with thenumber and layout of the display boxes 721 to 724 in the layout area720. In accordance with the display of the search query image in themedical image viewer 610 illustrated in FIG. 5, the thumbnail image ofthe search query image is initially displayed in the display box 721.

Each of the other display boxes 722 to 724 shows a thumbnail image of asimilar case in accordance with an image displayed in the correspondingone of the medical image viewers 620 to 640. That is, when the inputcontrol unit 103 detects that one of the thumbnail images displayed inthe case display area 710 has been dragged and dropped onto one of thedisplay boxes 722 to 724, the display control unit 104 causes thethumbnail image to be displayed in the display box, and also causes theslice image corresponding to the thumbnail image to be displayed in themedical image viewer corresponding to the display box. Accordingly, themedical image viewers 610 to 640 are associated with the display boxes721 to 724 in a one-to-one correspondence.

In the example illustrated in FIG. 6, the display boxes 722 to 724 areblank, and the medical image viewers 620 to 640 illustrated in FIG. 5are also blank accordingly.

The user performs a drag-and-drop operation using the mouse to move thethumbnail image that the user wishes to observe in more detail from thecase display area 710 to the layout area 720. For example, when the usermoves a thumbnail image to the display box 722, the slice imagecorresponding to the thumbnail image is displayed in the medical imageviewer 620 corresponding to the display box 722. Also, when the usermoves a thumbnail image to the display box 723, the slice imagecorresponding to the thumbnail image is displayed in the medical imageviewer 630 corresponding to the display box 723. That is, a thumbnailimage is moved to any display box among the display boxes 721 to 724,resulting in a thumbnail image of a similar case being displayedadjacent to the thumbnail image of the search query image. This enablesthe user to compare the case to be diagnosed and the similar case on thelevel of thumbnail images and to quickly determine the similaritybetween the two cases. Since thumbnail images have a smaller amount ofinformation than slice images, the user is able to roughly estimate howmuch the case to be diagnosed and the similar case which is adjacent inthe layout area 720 are similar. This enables the user to efficientlynarrow a large number of similar cases displayed in the case displayarea 710 down to a final set of candidates of similar cases to becompared with the target case to be diagnosed in more detail on thelevel of slice images.

The search query image and the slice image of the similar case are alsodisplayed on the display 101 a in the same position and layout as thosein the layout area 720. After the completion of narrowing down to afinal set of candidates of similar cases in the layout area 720, thecase to be diagnosed and similar cases obtained as the final set ofcandidates are displayed on the display 101 a on the level of sliceimages without inputting any operation. This guides the user smoothly tothe next operation step of detailed image interpretation of the case tobe diagnosed and the similar cases obtained as the final set ofcandidates.

The disease list display area 730 with the heading “disease list” isdisplayed in an upper left portion of the basic screen illustrated inFIG. 6. The disease list display area 730 shows the names of thedefinitely diagnosed diseases of all the similar cases obtained as aresult of the similar case search. The case to be diagnosed is labeledthe name of a definitely diagnosed disease after diagnosis, and is thenaccumulated in the case search system 300 as a similar case. Thus, eachsimilar case is labeled in advance the name of a definitely diagnoseddisease which is obtained through diagnosis.

FIG. 17 is an enlarged view of the disease list display area 730. InFIG. 17, the names of definitely diagnosed diseases are displayedseparately as the names of major-category diseases (731, 734, 737, 741,and 744) and the names of subcategory diseases (732, 733, 735, 736, 738,739, 740, 742, 743, and 745). In the example illustrated in FIG. 17,“mycosis” 731, “neoplastic” 734, “nonneoplastic” 737, “mycobacteriosis”741, and “other” 744 are displayed as the names of major-categorydiseases.

In the example illustrated in FIG. 17, furthermore, “aspergillosis” 732and “cryptococcosis” 733 are displayed as the names of subcategorydiseases of the “mycosis” 731. Further, “lung cancer” 735 and“metastatic lung cancer” 736 are displayed as the names of subcategorydiseases of the “neoplastic” 734. Further, “lung abscess” 738,“sarcoidosis” 739, and “septic emboli” 740 are displayed as the names ofsubcategory diseases of the “nonneoplastic” 737. Further,“nontuberculous mycobacteria (NTM)” 742 and “tuberculosis” 743 aredisplayed as the names of subcategory diseases of the “mycobacteriosis”741. Further, “bronchiectasis” 745 is displayed as the name of asubcategory disease of the “other” 744.

Further, next to the names of the major-category diseases and thesubcategory diseases are the numbers of cases of the respectivediseases. By selecting a row corresponding to any of the names of themajor-category diseases or subcategory diseases in the disease listdisplay area 730, the user can refine the similar cases to be displayedin the case display area 710. As illustrated in FIG. 6, immediatelyafter a similar case search is made, 62 similar cases including diversediseases and disorders are set as targets to be displayed. As a resultof clicking on the row corresponding to the “mycosis” 731 in FIG. 17with the mouse, as illustrated in FIG. 18, the display control unit 104displays similar cases of mycosis in the case display area 710. As aresult of clicking on the row corresponding to the “metastatic lungcancer” 736 in FIG. 17 with the mouse, as illustrated in FIG. 19, thedisplay control unit 104 displays similar cases of metastatic lungcancer in the case display area 710.

In this case, the display control unit 104 displays the name of thedisease used for refinement in the display condition display area 714 sothat the user can identify how the similar cases currently beingdisplayed in the case display area 710 have been refined. FIG. 18 is adiagram illustrating the basic screen K2 on which similar cases arerefined according to “mycosis”. FIG. 19 is a diagram illustrating thebasic screen K2 on which similar cases are refined according to“metastatic lung cancer”.

In the example illustrated in FIG. 18, “mycosis” is displayed in thedisplay condition display area 714 since refinement is performed inaccordance with “mycosis”. In the example illustrated in FIG. 19,“metastatic lung cancer” is displayed in the display condition displayarea 714 since refinement is performed in accordance with “metastaticlung cancer”.

In this case, furthermore, the display control unit 104 displays thenumber of similar cases in the number-of-search-result display area 713so that the user can identify the number of similar cases currentlybeing displayed in the case display area 710. Since there are 14 similarcases of “mycosis”, “14 results” is displayed in thenumber-of-search-result display area 713 in the example illustrated inFIG. 18. Since there are three similar cases of “metastatic lungcancer”, “3 results” is displayed in the number-of-search-result displayarea 713 in the example illustrated in FIG. 19.

With the function described above, similar cases of a disease suspectedby a physician as a target of image-based diagnosis are displayed in thecase display area 710, enabling the physician to easily make sure thatthe case to be diagnosed is consistent with the suspected disease.

In FIG. 18, thumbnail images of M (in FIG. 18, M=14) similar cases aredisplayed in the case display area 710 with the maximum number ND ofresults allowed to be displayed (in this embodiment, ND=20).

The distribution list display area 750 with the heading “distributionsof lesions” is displayed in a left middle portion of the basic screen K2illustrated in FIG. 6. The distribution list display area 750 showstypes of distributions of lesions seen in all the similar cases obtainedfrom the case search system 300 as a result of the similar case search.

FIG. 20 is an enlarged view of the distribution list display area 750.In the example illustrated in FIG. 20, the names of seven distributionsof lesions are displayed, and checkboxes are displayed to the left ofthe respective names of the distributions of lesions. In the exampleillustrated in FIG. 20, “diffuse” 751, “segmental” 752, “bronchial” 753,“bilateral” 754, “multiple” 755, “subpleural” 756, and “hematogenous”757 are displayed as distributions of lesions.

The distributions of lesions described above are defined in advance, andeach similar case is given in advance a distribution flag value (“1” forApplicable or “0” for Not Applicable) indicating the applicability ofthe similar case to each of the “diffuse” 751 to the “hematogenous” 757.In some similar cases, the distribution flag values for all thedistributions of lesions may be set to Not Applicable (“0”), and, inother similar cases, the distribution flag values for a plurality ofdistributions of lesions may be set to Applicable (“1”).

The case search system 300 according to this embodiment searches for asimilar case that has a region of interest similar to a region ofinterest set by a user in a slice image of the case to be diagnosed. Alesion may be present in a slice image other than the slice image inwhich the region of interest has been set by the user. Further, the usermay wish to, after searching for a similar case on the basis of theslice image in which the region of interest has been set, compare aslice image other than the slice image in which the region of interesthas been set with the similar case found as a result of the search. Inthis case, the user inputs a slice-based forwarding operation on themedical image viewer 610 to display a different slice image, andcompares the displayed slice image with the found similar case. If asimilar case related to the lesion of interest among all the similarcases found as a result of the search is displayed in the case displayarea 710, the operation of extracting a slice image having the desiredlesion from among slice images other than the slice image in which theregion of interest has been set can be smoothly performed. Accordingly,this embodiment provides a function of refining the found similar casesaccording to the desired distribution of lesions to make the operationdescribed above smoother.

In this embodiment, the “diffuse” 751 to the “hematogenous” 757illustrated in FIG. 20 are used as distributions of lesions in thepulmonary field. In addition, as illustrated in FIG. 20, the displaycontrol unit 104 displays the checkboxes and the names of thedistributions of lesions in such a manner that the distributions oflesions available for refinement are active and the distributions oflesions not available for refinement are inactive. Here, being “active”refers to having higher luminance than the state of being “inactive”,and being “inactive” refers to having lower luminance than the state ofbeing “active”.

In the example illustrated in FIG. 20, the “diffuse” 751 and the“bronchial” 753 to the “hematogenous” 757 are displayed as active,whereas the “segmental” 752 is inactive, because of the followingreasons: The distribution flag values for the “diffuse” 751 and the“bronchial” 753 to the “hematogenous” 757 are currently set to “1”(Applicable) in at least one similar case among all the similar casesobtained through the similar case search, whereas the distribution flagvalue for the “segmental” 752 is currently set to “0” (Not Applicable)in all the obtained similar cases.

When the input control unit 103 detects that one or more of the activecheckboxes have been checked, the display control unit 104 causessimilar cases that meet the lesion condition(s) for which the checkboxhas been checked to be displayed in the case display area 710.

Note that the distribution flag value for the “segmental” 752 is set to“0” (Not Applicable) in any of the similar cases obtained as a result ofthe search. Thus, if the checkbox for the “segmental” 752 is allowed tobe checked, even though the checkbox for such a distribution of lesionsis checked, no similar case will be displayed in the case display area710. In this case, it is meaningless to check the checkbox. To avoidthis situation, in this embodiment, a distribution of lesions for whichthe distribution flag value is set to “0” (Not Applicable) in any of thesimilar cases obtained as a result of the search is displayed asinactive.

FIG. 21 is a diagram illustrating the distribution list display area 750in which the checkbox for the “bilateral” 754 is checked. FIG. 22 is adiagram illustrating the basic screen K2 on which refinement isperformed in accordance with the distribution of lesions identified bythe “bilateral” 754. As illustrated in FIG. 21, when the checkbox forthe “bilateral” 754 is checked, as illustrated in FIG. 22, the displaycontrol unit 104 displays similar cases exhibiting bilateral lesiondistribution in the case display area 710. In the illustrated example,ten similar cases exhibiting bilateral lesion distribution. Thus, thedisplay control unit 104 displays “10 results” in thenumber-of-search-result display area 713. The display control unit 104further displays the name of the disease being displayed and the name ofthe distribution of lesions, i.e., “bilateral”, in the display conditiondisplay area 714. In the example illustrated in FIG. 22, there is norefinement according to a disease name in the disease list display area730, “all diseases and disorders” is displayed in the display conditiondisplay area 714.

As illustrated in FIG. 21, if the checkbox for the “bilateral” 754 ischecked, as illustrated in FIG. 22, the display control unit 104displays a thumbnail image enlarged by the enlarged image generationunit 112 with the enlargement factor corresponding to the distributionof lesions selected by the case display area 710. If the name of thedistribution of lesions “bilateral” is selected, it is desirable thatthe user be able to observe both sides of the lungs. Accordingly, theenlarged image generation unit 112 sets the enlargement factor to 1.0.The display control unit 104 displays thumbnail images with anenlargement factor of 1.0.

Similarly, if the checkbox for the “multiple” 755 is checked, thedisplay control unit 104 displays similar cases exhibiting multiplelesion distribution in the case display area 710. When the name of thedistribution of lesions “multiple” is selected, it is desirable that theuser be able to observe a distribution of multiple lesions. Accordingly,the enlarged image generation unit 112 sets the enlargement factor to1.0. The display control unit 104 displays thumbnail images with anenlargement factor of 1.0.

Similarly, if the checkbox for the “diffuse” 751 is checked, the displaycontrol unit 104 displays similar cases exhibiting diffuse lesiondistribution in the case display area 710. If the name of thedistribution of lesions “diffuse” is selected, it is desirable that theuser be able to observe distributions of diffuse lesions extending overa large area. Accordingly, the enlarged image generation unit 112 setsthe enlargement factor to 1.0. The display control unit 104 displaysthumbnail images with an enlargement factor of 1.0.

Similarly, if the checkbox for the “hematogenous” 757 is checked, thedisplay control unit 104 displays similar cases exhibiting hematogenouslesion distribution in the case display area 710. If “hematogenous” isselected, there is a possibility that a metastasis of a lesion otherthan the lesion of interests may occur. Thus, it is desirable to observethe entire image. Accordingly, the enlarged image generation unit 112sets the enlargement factor to 1.0. The display control unit 104displays thumbnail images with an enlargement factor of 1.0.

FIG. 23 is a diagram illustrating the distribution list display area 750in which the checkbox for the “bronchial” 753 is checked. FIG. 24 is adiagram illustrating the basic screen K2 on which refinement isperformed in accordance with the distribution of lesions identified bythe “bronchial” 753. As illustrated in FIG. 23, if the checkbox for the“bronchial” 753 is checked, as illustrated in FIG. 24, the displaycontrol unit 104 displays similar cases exhibiting bronchial lesiondistribution in the case display area 710. In the illustrated example,12 similar cases exhibit bronchial lesion distribution. Thus, thedisplay control unit 104 displays “12 results” in thenumber-of-search-result display area 713. The display control unit 104further displays, in the display condition display area 714, the name ofthe disease being displayed and the name of the distribution of lesions,i.e., “bronchial”. In the example illustrated in FIG. 24, there is norefinement according to any of the disease names listed in the diseaselist display area 730, and “all diseases and disorders” is displayed inthe display condition display area 714.

As illustrated in FIG. 23, if the checkbox for the “bronchial” 753 ischecked, as illustrated in FIG. 24, the display control unit 104displays, in the case display area 710, thumbnail images enlarged by theenlarged image generation unit 112 with the enlargement factorcorresponding to the selected distribution of lesions. If the name ofthe distribution of lesions “bronchial” is selected, it is desirablethat the user be able to determine whether or not each result isbronchial. Accordingly, the enlarged image generation unit 112determines an enlargement factor so that the area of each region ofinterest is equal to approximately one half of the area of the displayarea. The display control unit 104 displays thumbnail images enlarged bythe enlarged image generation unit 112.

Similarly, if the checkbox for the “segmental” 752 is checked, thedisplay control unit 104 displays similar cases exhibiting havingsegmental lesion distribution in the case display area 710. If the nameof the distribution of lesions “segmental” is selected, it is desirablethat the user be able to observe the details of segmental lesions.Accordingly, the enlarged image generation unit 112 determines anenlargement factor so that the area of each region of interest is equalto approximately one half of the area of the display area. The displaycontrol unit 104 displays thumbnail images enlarged by the enlargedimage generation unit 112.

FIG. 25 is a diagram illustrating the distribution list display area 750in which the checkbox for the subpleural 756 is checked. FIG. 26 is adiagram illustrating the basic screen K2 on which refinement isperformed in accordance with the distribution of lesions identified bythe subpleural 756. As illustrated in FIG. 25, if the checkbox for thesubpleural 756 is checked, as illustrated in FIG. 25, the displaycontrol unit 104 displays similar cases exhibiting subpleural lesiondistribution in the case display area 710. In the illustrated example,seven similar cases exhibit subpleural lesion distribution. Thus, thedisplay control unit 104 displays “7 results” in thenumber-of-search-result display area 713. The display control unit 104further displays the name of the disease being displayed and the name ofthe distribution of lesions, i.e., “subpleural”, in the displaycondition display area 714. In the example illustrated in FIG. 26, norefinement is performed in accordance with any of the disease nameslisted in the disease list display area 730. Thus, “all diseases anddisorders” is displayed in the display condition display area 714.

As illustrated in FIG. 25, if the checkbox for the subpleural 756 ischecked, as illustrated in FIG. 26, the display control unit 104displays, in the case display area 710, thumbnail images enlarged by theenlarged image generation unit 112 with the enlargement factorcorresponding to the selected distribution of lesions. If the name ofthe distribution of lesions “subpleural” is selected, it is desirablethat the user be able to observe a positional relationship with thepleura. Accordingly, the enlarged image generation unit 112 determinesan enlargement factor so that the pleura is included. The displaycontrol unit 104 displays thumbnail images enlarged by the enlargedimage generation unit 112.

The thumbnail images displayed in the case display area 710 are designedso that the display areas thereof can be changed by a user operationeven when the thumbnail images are refined according to a predeterminedistribution of lesions.

Note that, as illustrated in FIG. 21, if the checkbox for the“bilateral” 754 is checked, as described above, the display control unit104 displays thumbnail images enlarged by the enlarged image generationunit 112 with a factor of 1.0. Accordingly, as illustrated in FIG. 22,the original thumbnail images are displayed in their entirety. In thiscase, the display area is not changed.

In contrast, as illustrated in FIG. 23, if the checkbox for the“bronchial” 753 is checked, as illustrated in FIG. 24, each of thethumbnail images is enlarged and displayed. Accordingly, in response toinstructions given by the user for causing a display area to move, thedisplay areas of the thumbnail images are caused to move.

FIG. 27 is a diagram schematically illustrating a drag operation 2701performed by a user while the basic screen K2 illustrated in FIG. 24 isbeing displayed. When the user performs the drag operation 2701, theinput control unit 103 detects the amount of movement of the mouse, andnotifies the enlarged image generation unit 112 of the detected amountof movement. Then, the enlarged image generation unit 112 determines anamount of movement of a display area in a thumbnail image by using thedetected amount of movement of the mouse, and generates a thumbnailimage in which the display area has moved the determined amount. Thedisplay control unit 104 displays, in the case display area 710,thumbnail images that have been caused to move by the enlarged imagegeneration unit 112.

As illustrated in FIG. 25, if the checkbox for the subpleural 756 ischecked, as illustrated in FIG. 26, the individual thumbnail images areenlarged and displayed. Accordingly, in response to instructions givenby the user for causing a display area to move, the display areas of thethumbnail images are caused to move.

FIG. 28 is a diagram schematically illustrating a drag operation 2801performed by a user while the basic screen K2 illustrated in FIG. 26 isbeing displayed. When the user performs the drag operation 2801, theinput control unit 103 detects the amount of movement of the mouse, andnotifies the enlarged image generation unit 112 of the detected amountof movement. Then, the enlarged image generation unit 112 determines anamount of movement of a display area in a thumbnail image by using thedetected amount of movement of the mouse, and generates a thumbnailimage in which the display area has moved the determined amount. Thedisplay control unit 104 displays, in the case display area 710,thumbnail images that have been caused to move by the enlarged imagegeneration unit 112.

The process for enlarging each thumbnail image and the display areamovement process when a distribution of lesions is selected in FIG. 22,FIG. 24, and FIG. 26 will be described in detail below.

FIG. 29 is a diagram illustrating the data configuration of the patientinformation 1000. The patient information 1000 is accumulated in thepatient information accumulation unit 201 on a patient-by-patient basis,and is managed by the patient information management unit 202 of themedical information management system 200. The patient information 1000has personal information on each patient, such as the gender and age,clinical information such as the past medical history, and testinformation on medical tests such as a blood test. As illustrated inFIG. 29, the patient information 1000 includes a patient ID 1100, a name1200, an age 1300, a gender 1400, a past medical history 1500, a familyhistory 1600, a chief complaint 1700, test information 1800, and adefinite diagnosis 1900.

The patient ID 1100 is an identifier specific to the patient. The name1200, the age 1300, the gender 1400, the past medical history 1500, thefamily history 1600, and the chief complaint 1700 are the name, age,gender, past medical history, family history, and chief complaint of thepatient identified by the patient ID 1100, respectively. The testinformation 1800 indicates information concerning one or more medicaltests that the patient has already undergone, as illustrated in FIG. 30.

FIG. 30 is a diagram illustrating the data configuration of the testinformation 1800 illustrated in FIG. 29. The test information 1800 isinformation concerning tests performed on the patient, and a piece oftest information is created for each test. The test information 1800includes a test ID 1810, a test date 1820, a test type 1830, and a testresult 1840. The test ID 1810 is an identifier specific to each test.The test date 1820 is the date on which the test was performed. The testtype 1830 is the type of the test. Examples of the type of the testinclude blood tests, respiratory tests, endoscopic examinations, simpleX-ray imaging tests, and CT imaging tests.

The test result 1840 includes the values of various indices, such aswhite blood cell count (or leukocyte count), lactate dehydrogenase(LDH), and glutamic-pyruvic transaminase (GPT) for a blood test. Thetest result 1840 also includes, for example, a decision made by aphysician based on various indices. For an imaging test such as a simpleX-ray imaging test or a CT imaging test, the test result 1840 includespointer information on a pointer to a captured image and pointerinformation on a pointer to a report obtained as a result of image-baseddiagnosis. Images captured during tests are accumulated in DICOM formatin the medical image data accumulation unit 203 of the medicalinformation management system 200.

In a case where the test type 1830 is an imaging test such as simpleX-ray, CT, MRI, or positron emission tomography (PET), medical imagedata obtained with such imaging tests is accumulated in a medical imagedatabase 2000 stored in the medical image data accumulation unit 203 ofthe medical information management system 200.

FIG. 31 is a diagram illustrating the data configuration of the medicalimage database 2000. The medical image database 2000 includes a test ID1810 and a series ID 2100. A plurality of series IDs 2100 may beassociated with a single test ID 1810 since a plurality of types ofimaging sessions (e.g., simple CT, contrast CT, etc.) may be performedin a single test. That is, a number of series corresponding to thenumber of types of imaging sessions are obtained.

A series is also obtained for each condition of the reconstruction ofcaptured images, as well as for each type of imaging session. Forexample, when captured images are reconstructed under the pulmonarycondition and the mediastinal condition, one series is obtained for eachof these conditions. In images reconstructed under the pulmonarycondition, blood vessels in the lungs, bronchi, alveoli, and the likeare displayed highlighted. In images reconstructed under the mediastinalcondition, the mediastinal structures, such as blood vessels and lymphnodes, are displayed highlighted. The pulmonary condition and themediastinal condition are obtained by the reconstruction of imagesobtained in single imaging sessions. Thus, two imaging sessions, orsimple CT and contrast CT, are performed, and images are reconstructedunder the pulmonary condition and the mediastinal condition in each ofthe two imaging sessions, thereby obtaining two series for the pulmonarycondition and two series for the mediastinal condition.

For imaging tests such as CT and MRI, a plurality of slice images areobtained in a single imaging session. Thus, a plurality of slice IDs2200 are associated with one series ID 2100. In FIG. 31, two series IDs“CT149123” and “CT149124” are associated with the test ID “13227989”.Thus, it is found that CT images of two series have been obtained withthe test. It is also found that a plurality of slice IDs 2200 areassociated with each of the series IDs “CT149123” and “CT149124”.

In a case where the test type 1830 is an imaging test such as simpleX-ray, CT, MRI, or PET, a diagnostic report 3000 as illustrated in FIG.32 is accumulated in the diagnostic report management unit 205 of themedical information management system 200. The diagnostic report 3000includes a diagnosis from a physician for each test.

FIG. 32 is a diagram illustrating the data configuration of thediagnostic report 3000. The diagnostic report 3000 includes a test ID1810, findings 3100, and a diagnosis 3200. The test ID 1810 is the sameas the test ID 1810 illustrated in FIG. 30. Accordingly, the diagnosticreport 3000 and the test information 1800 are associated with eachother. The findings 3100 include a note indicating the physician'sfindings of the test. The diagnosis 3200 includes a note indicating thephysician's diagnosis for the test.

FIG. 33 is a diagram illustrating the data configuration of the similarcase data 4000. The similar case data 4000 is data to be referred to inorder to search for a similar case that is similar to the case to bediagnosed, and a piece of similar case data is created for each similarcase. The similar case data 4000 is an example of attached informationattached to a similar case. The similar case data 4000 is accumulatedfor each similar case in the similar case data accumulation unit 301 ofthe case search system 300. As illustrated in FIG. 33, the similar casedata 4000 includes a similar case ID 4100, a slice ID 4200,region-of-interest information 4300, image feature data 4400, thumbnailimage data 4500, distribution-of-lesion information 4600, a definitediagnosis (major-category disease name) 4700, and a definite diagnosis(subcategory disease name) 4800.

The similar case ID 4100 is an identifier of the similar case data 4000.Since a piece of similar case data is generated for each region ofinterest set on a slice image of a similar case, the similar case ID4100 can also be referred to as an identifier of the region of interest.In the example illustrated in FIG. 33, the similar case ID 4100 isconstituted by a symbol sequence including “SIM” and a number whichfollows it.

The slice ID 4200 is an identifier of a slice image in which a region ofinterest is set, and is the same as the slice ID 2200 illustrated inFIG. 31. The region-of-interest information 4300 is informationindicating the position of the region of interest set on the sliceimage. FIG. 34 is a diagram schematically illustrating a region ofinterest ROI set on a slice image 3101. In the example illustrated inFIG. 34, the region of interest ROI has a rectangular shape. Thus, theregion-of-interest information 4300 includes four values, namely, thecoordinates (xl, yt) of the upper left corner of the region of interestROI and the coordinates (xr, yb) of the lower right corner of the regionof interest ROI. The region of interest ROI may also be of any othershape than rectangular, in which case a parameter capable of uniquelyidentifying the region is used as the region-of-interest information4300. For example, the region of interest ROI may be circular. In thiscase, the coordinates of the center of the circular region and theradius of the circular region may be used as the region-of-interestinformation 4300.

The image feature data 4400 is certain-number dimensional (here,N-dimensional) feature values extracted from the region of interestdefined in the region-of-interest information 4300. The thumbnail imagedata 4500 is image data of a thumbnail image generated based on a DICOMslice image identified by the slice ID 4200 for display in the casedisplay area 710. In the thumbnail image data 4500, for example, pixelvalues of the thumbnail image are arranged in raster scan order from theupper left corner to the lower right corner of the thumbnail image. Asdescribed previously, a DICOM image obtained with a CT test is an 11-bitimage having a size of 512 pixels×512 pixels (with a pixel value of−1000 to +1000). In this embodiment, accordingly, to increase the speedof display of a thumbnail image, a DICOM image on which the thumbnailimage is based is subjected to resolution reduction and grayscaleconversion to create a thumbnail image with 8-bit pixel values inadvance, and the resulting thumbnail image is registered in the similarcase data 4000. Thumbnail images may be created by, for example, themedical information management system 200, and transmitted to the casesearch system 300. Alternatively, thumbnail images may be created by thecase search system 300 by obtaining DICOM images from the medicalinformation management system 200.

The distribution-of-lesion information 4600 is a distribution flag value(“1” for Applicable or “0” for Not Applicable) indicating theapplicability of the target similar case to each of the predetermineddistributions of lesions identified by “diffuse” 4610, “segmental” 4620,“bronchial” 4630, “bilateral” 4640, “multiple” 4650, “subpleural” 4660,and “hematogenous” 4670.

The definite diagnosis (major-category disease name) 4700 indicates thename of a disease that is definitely diagnosed in the target similarcase and that is classified as a major category (hereinafter referred toas a “major-category disease”). The definite diagnosis (major-categorydisease name) 4700 is used to refine similar cases according to amajor-category disease name.

The definite diagnosis (subcategory disease name) 4800 indicates thename of a disease that is definitely diagnosed in the target similarcase and that is classified as a subcategory (hereinafter referred to asa “subcategory disease”). The definite diagnosis (subcategory diseasename) 4800 is used to refine similar cases according to a subcategorydisease name.

In the definite diagnosis (major-category disease name) 4700, the nameof a major-category disease that is uniquely associated with thedefinite diagnosis (subcategory disease name) 4800 is defined inadvance. The definite diagnosis (major-category disease name) 4700 isstored in the similar case data 4000 using the association relationshipbetween them.

In the definite diagnosis (subcategory disease name) 4800, a series ID2100 is identified in the medical image data accumulation unit 203 by aslice ID 2200 illustrated in FIG. 31. Further, a test ID 1810 isidentified in the patient information accumulation unit 201 by theidentified series ID 2100, and associated patient information 1000 (FIG.29) is identified by the test ID 1810. Accordingly, the definitediagnosis 1900 of the patient is identified by the identified patientinformation 1000.

Next, a process from the start of image interpretation to the start of asimilar case search by using the information terminal 100 incoordination with the medical information management system 200 and thecase search system 300 will be described.

FIG. 35 is a sequence diagram illustrating a process performed during aperiod in which the information terminal 100 obtains a case to bediagnosed from the medical information management system 200 and thensends a similar case search request to the case search system 300 andthe case search system 300 receives the similar case search request. InFIG. 35, rectangular objects to the left of the sequence diagram, whichare arranged side-by-side in two lines, represent screens displayed onthe displays 101 a and 101 b through the processing of the respectivesteps. In FIG. 35, furthermore, in the information terminal 100, “A”represents the medical information management application, and “B”represents the similar case search application. It is assumed that themedical information management application is started in advance beforethe commencement of the above-described sequence.

First, the information terminal 100 accepts a request for displaying atest list in which image interpretation is to be performed by a user (aspecialist who provides image interpretation) through the operation unit102, and transmits the request for displaying the test list to thecommunication control unit 206 of the medical information managementsystem 200 via the input control unit 103 and the communication controlunit 110 (S510).

The patient information management unit 202 of the medical informationmanagement system 200 lists tests in which image interpretation has yetto be performed after the completion of an imaging test to generate atest list in which image interpretation is to be performed. Then, thepatient information management unit 202 transmits the generated testlist to the communication control unit 110 of the information terminal100 via the communication control unit 206 (S520). The test listincludes the patient information 1000 on the patient, and the testinformation 1800.

The display control unit 104 of the information terminal 100 displaysthe test list received by the communication control unit 110 on thedisplay 101 (S530).

In this case, the test list is displayed on the display 101 a, whereasno image is displayed on the display 101 b.

FIG. 36 is a view of a test list screen. The test list includes an area800 where tests with image interpretation yet to be performed aredisplayed, and an area 810 where information concerning series includedin the tests is displayed. The area 800 has the following fields:“patient ID”, “patient name”, “test date”, “test ID”, and “test type”.The “patient ID” and “patient name” fields show the patient ID 1100 andthe name 1200 registered in the patient information 1000, respectively.The “test date”, “test ID”, and “test type” fields show the test date1820, the test ID 1810, and the test type 1830 registered in the testinformation 1800, respectively. The area 810 is an area for displayingthe details of a test selected by the user in the area 800, and has thefollowing fields: “series ID”, “definition”, and “image”. In FIG. 36, notest (corresponding to each row) is selected by the user in the area800, and thus no image is displayed in the area 810.

The user selects a test in which image interpretation is about to beperformed from among the tests displayed in the area 800. When theselection of the test is detected by the input control unit 103, asillustrated in FIG. 35, the communication control unit 110 transmits arequest for displaying all the series included in the test ID of theselected test to the medical information management system 200 (S540).

When the communication control unit 206 of the medical informationmanagement system 200 receives the request, the patient informationmanagement unit 202 refers to the medical image database 2000illustrated in FIG. 31 to obtain all the slice images in all the seriesincluded in the test ID designated in the request, and transmits theslice images to the information terminal 100 via the communicationcontrol unit 206 (S550). For example, in the example illustrated in FIG.31, when the test with the test ID “13227989” is selected by the user,all the slice images included in the series with the series IDs“CT149123” and “CT149124” are transmitted in S550.

When the communication control unit 110 of the information terminal 100obtains the images in all the series, the display control unit 104displays a series list in the area 810 to display information concerningall the series included in the designated test ID in list form (S560).

In this case, the area 810 for a test list, which is displayed on thedisplay 101 a, shows a list of series corresponding to the test selectedin the area 800, whereas no image is displayed on the display 101 b.

FIG. 37 is a view of a test list screen obtained after a test isselected. In the area 800 illustrated in FIG. 37, a selected row ishighlighted. In the example illustrated in FIG. 37, the test for “JohnDoe” in the second row is selected in the area 800. Accordingly, the“series IDs”, “definitions”, and “images” for the selected test aredisplayed in the area 810. The series IDs associated with the test ID ofthe selected test in the medical image database 2000 are displayed inthe “series ID” field, and thumbnail images of single typical sliceimages of the displayed series IDs are displayed in the “image” field.Each of the single typical slice images of the series IDs is an imagecorresponding to a predetermined slice position. The predetermined sliceposition may be the initial slice position or the center slice position.The “definition” indicates an imaging condition or a reconstructioncondition for the associated series. The “definition” is registered inassociation with, for example, a series ID 2100 in the medical imagedatabase 2000 in FIG. 31, although not illustrated in the drawings.

When the user selects a series to be interpreted in the area 810 and theselection of the series is detected by the input control unit 103, asillustrated in FIG. 38, the display control unit 104 displays theinitial slice image in the selected series on the display 101 a (S570).FIG. 38 is a diagram illustrating a slice image displayed on the display101 a when a user selects a series. FIG. 38 is a diagram illustratingthe first slice in chest CT imaging, and illustrates a slice image of ashoulder part which is nearer the head than the apex of the lung. Thedisplay control unit 104 displays all the slice images in the selectedseries on the display 101 a so that a slice-based forwarding operationcan be performed. No image is displayed on the display 101 b. Forexample, the user inputs a slice-based forwarding operation whichinvolves rotating the mouse wheel while the mouse pointer is on thedisplay 101 a, and the input operation is detected by the input controlunit 103. Then, the display control unit 104 switches the slice imagedisplayed on the display 101 a to a slice image corresponding to anotherslice position in accordance with the amount of rotation of the mousewheel. The user performs image-based diagnosis while inputting aslice-based forwarding operation. When confused about image-baseddiagnosis, the user starts the similar case search application.

The similar case search application may be started in response to theinput of a predetermined shortcut key on the keyboard of the operationunit 102, or may be started by specifying a similar case search menufrom a medical image viewer menu which is displayed in response to theright click of the mouse. When an instruction is given to start thesimilar case search application, the management of the informationterminal 100 is passed to the ROI management unit 105, and theinformation terminal 100 waits for a region of interest (ROI) to bereceived.

The user sets a region of interest (ROI) on a lesion in the slice imagedisplayed on the display 101 a through the operation unit 102 (S580). Asillustrated in FIG. 34, the user may enter the coordinates of the upperleft corner of the region of interest ROI in the slice image 3101 by,for example, left-clicking on the mouse. Then, the user may drag themouse diagonally down from left to right while left-clicking on themouse and then release the left click to enter the coordinates of thelower right corner of the region of interest ROI.

When the input control unit 103 detects the operation of setting aregion of interest, the ROI management unit 105 receives coordinate dataof the upper left and lower right corners of the region of interest fromthe input control unit 103, and generates region-of-interest informationby using the received coordinate data. Then, the ROI management unit 105transmits the generated region-of-interest information to thecommunication control unit 110 (S590).

Also, the ROI management unit 105 transmits the slice image of the caseto be diagnosed to the communication control unit 110 (S600). In thiscase, one slice image (i.e., a search query image) in which the user hasset a region of interest in the series selected by the user among theslice images in all the series received by the information terminal 100from the medical information management system 200 in S550 istransmitted.

Then, the communication control unit 110 receives the region-of-interestinformation transmitted from the ROI management unit 105, and transmitsthe region-of-interest information to the communication control unit 304of the case search system 300 (S601).

Also, the communication control unit 110 receives the slice imagetransmitted from the ROI management unit 105, and transmits the sliceimage to the communication control unit 304 of the case search system300 (S602).

In S600 and S601, a slice image itself is transmitted. The slice ID of aslice image may be transmitted instead. In this case, upon receipt ofthe slice ID, the case search system 300 may acquire a slice image fromthe medical information management system 200 by specifying the sliceID.

Next, a process performed during a period in which the case searchsystem 300 performs a similar case search and the information terminal100 initially displays similar case search results will be described.

FIG. 39 is a sequence diagram illustrating a process performed during aperiod in which, after receiving a similar case search request, the casesearch system 300 returns similar case search results to the informationterminal 100.

The image feature extraction unit 302 of the case search system 300extracts predetermined multi-dimensional image features from the regionof interest set on the search query image (S610).

Examples of the “image features” include image features for the shape oforgans or lesions in medical images, and image features for a luminancedistribution. For example, NEMOTO et al. describes, in “Improvement ofTumor Detection Performance in Mammograms by Feature Selection from aLarge Number of Features and Proposal of Fast Feature Selection Method”,the transactions of the Institute of Electronics, Information andCommunication Engineers D-II, Vol. J88-D-II, No. 2, pp. 416-426,February 2005, the use of 490-dimensional image features. In thisembodiment, for example, the image features described in this non-patentliterature are used. However, this is merely an example, and other imagefeatures may be used.

The similar case search unit 303 compares the image feature extracted bythe image feature extraction unit 302 with an image feature in each ofthe similar cases accumulated in the similar case data accumulation unit301 (S620). The similar case search unit 303 compares the two imagefeatures by calculating a distance between image feature data extractedfrom the search query image and the image feature data 4400 registeredin the similar case data 4000 (FIG. 33) accumulated for each similarcase in the similar case data accumulation unit 301.

Then, the similar case search unit 303 sorts similar cases for which thedistance is less than or equal to a predetermined threshold value inorder of increasing distance, and determines the resulting similar casesas similar cases to be transmitted (S630). Then, the communicationcontrol unit 304 transmits, within the similar case data 4000accumulated in the similar case data accumulation unit 301, the similarcase ID 4100 of the similar cases determined to be transmitted, theslice ID 4200, the region-of-interest information 4300, the thumbnailimage data 4500, the distribution-of-lesion information 4600, thedefinite diagnosis (major-category disease name) 4700, and the definitediagnosis (subcategory disease name) 4800, and further the distancecalculated by the similar case search unit 303 to the informationterminal 100 (S640).

Subsequently, a process for generating the initial basic screen K2 (FIG.6) on which similar case search results are displayed is executed.First, management information used to generate the layout area 720 onthe initial basic screen K2 will be described.

First, the communication control unit 304 of the case search system 300transmits layout information to the information terminal 100 (S650). Thelayout information is information for specifying the number of rows andcolumns of display boxes in the layout area 720.

Then, when the communication control unit 110 of the informationterminal 100 receives the layout information, the display box managementunit 106 registers the number of rows and columns of display boxes,which is specified in the transmitted layout information, in the displaybox management information 4410 (FIG. 40), and also registers the sliceID of the search query image in the display box management information4410 (FIG. 40) (S660).

FIG. 40 is a diagram illustrating the data configuration of the displaybox management information 4410. The display box management information4410 includes a table 4411 in which the number of rows and the number ofcolumns are registered, and a table 4412 in which the slice ID of aslice image to be displayed in each display box is registered.Accordingly, the display box management unit 106 registers the number ofrows and the number of columns, which are specified in the layoutinformation transmitted from the case search system 300, in anumber-of-row field and a number-of-column field of the table 4411. Inthis embodiment, the thumbnail image of the search query image isdisplayed in the upper left display box 721 among the four display boxes721 to 724. The display box management unit 106 registers the slice IDof the search query image transmitted from the medical informationmanagement system 200 in the “first row and first column” item of thetable 4412.

The default value of the number of rows and columns of display boxes inthe layout area 720 is set in advance by the case search system 300. Forexample, the default values of the number of rows and the number ofcolumns are two and two, respectively. Thus, “two rows and two columns”is registered in the display box management information 4410 illustratedin FIG. 40.

In the example illustrated in FIG. 6, the display boxes 721 to 724 aredisplayed in two rows and two columns in the layout area 720. The numberof rows and the number of columns in the layout area 720 is set by theuser as desired.

FIG. 41 is a diagram illustrating the basic screen K2, which includesthe layout area 720 in which display boxes are set in three rows and twocolumns. Given that the display boxes included in the layout area 720are generalized for a set of display boxes in M rows and N columns, ifM≠N, M>N is preferable when the display 101 is a portrait-orienteddisplay, and M<N is preferable when the display 101 is alandscape-oriented display.

One important feature of this embodiment is to display a thumbnail imageof a target case to be diagnosed in one of the display boxes included inthe layout area 720. That is, allowing the case to be diagnosed and asimilar case to be displayed adjacent to each other helps the userdetermine the similarity between the two cases. Thus, display boxes arepreferably arranged in up to three rows and up to three columns in thelayout area 720.

In a case where display boxes are arranged in three rows and twocolumns, the thumbnail image of the search query image is preferablydisplayed in the display box in the second row and the first column orin the display box in the second row and the second column. In a casewhere display boxes are arranged in two rows and three columns, thethumbnail image of the search query image is preferably displayed in thedisplay box in the first row and the second column or in the display boxin the second row and the second column. In a case where display boxesare arranged in three rows and three columns, the thumbnail image of thesearch query image is preferably displayed in the display box in thesecond row and the second column. With the configuration describedabove, a similar case is always displayed adjacent to the target case tobe diagnosed in the layout area 720.

The layout information on the layout area 720, which is set by the user,is registered in the layout management information 4200 illustrated inFIG. 42 or FIG. 43.

The box layout management unit 111 that stores the layout managementinformation 4200 may be included in the case search system 300.

Even the same user may change the layout of the layout area 720 so as tofit the size of the display 101 of the information terminal 100 or thetype of the screen (portrait-oriented or landscape-oriented).Accordingly, as illustrated in FIG. 42, layout information set by theuser may be registered in the layout management information 4200 inassociation with the user ID and the terminal ID. FIG. 42 is a diagramillustrating an example of the layout management information 4200. Inthe layout management information 4200, the “user ID”, the “terminalID”, the “number of columns”, the “number of rows”, and the “position ofcase to be diagnosed” are associated with each other. The “user ID”represents a user identifier assigned in advance to a user who uses theinformation terminal 100. The “terminal ID” represents an identifier ofan information terminal 100 that the user is expected to use.

In the example illustrated in FIG. 42, the user with the user ID “U01”is expected to use the information terminals with the terminal IDs “T02”and “T04”. Thus, the user ID “U01” is associated with the terminal IDs“T02” and “T04”. The “number of rows” and the “number of columns”contain the number of rows and the number of columns in the layout area720 set by the user. The “position of case to be diagnosed” representsthe position of a display box in which the case to be diagnosed isdisplayed. For example, the layout area 720 with two rows and threecolumns is set for the information terminal 100 with the terminal ID“T04”, and (2, 1) which indicates the second row and the first column isregistered as the “position of case to be diagnosed” in order to allowthe case to be diagnosed and all the similar cases to be displayedadjacent to each other.

In FIG. 42, an embodiment is given in which layout information ismanaged in association with a user ID and a terminal ID. Alternatively,layout information may be managed in association with a user ID. FIG. 43is a diagram illustrating an example of the layout managementinformation 4200. The layout management information 4200 illustrated inFIG. 43 does not include the “terminal ID” field, which is included inthe layout management information 4200 illustrated in FIG. 42. Exceptfor that, the layout management information 4200 of FIG. 43 and thelayout management information 4200 of FIG. 42 are the same. In theembodiment illustrated in FIG. 43, the “terminal ID” field is notincluded because one user is expected to use one information terminal100.

In a case where layout information is managed by the case search system300, in S650 in FIG. 39, layout information on the associated user istransmitted to the information terminal 100.

Then, the display control unit 104 generates the initial basic screen K2on which similar case search results are displayed, by using the similarcase data transmitted in S640 and the display box management information4410 stored in S660 (S670).

In this case, the basic screen K2 illustrated in FIG. 6 is displayed onthe display 101 b. Further, the search query image is displayed on thedisplay 101 a.

FIG. 44 is a flowchart illustrating the details of the process forgenerating the initial basic screen K2 illustrated in S670 in FIG. 39.

First, in S1000, the display control unit 104 counts the number ofsimilar cases received in S640 in FIG. 39, and displays the count valuein the number-of-search-result display area 713.

Then, in S1100, the display control unit 104 displays “all diseases anddisorders” in the display condition display area 714. Here, “alldiseases and disorders” is displayed because no refinement is performedin accordance with a disease name or a distribution of lesions by theuser on the initial basic screen K2.

Then, in S1200, the display control unit 104 displays in the casedisplay area 710 thumbnail images of similar cases, the number of whichis equal to the number of similar cases whose thumbnail images can bedisplayed in the case display area 710 among the similar cases receivedin S640 in FIG. 39, and also displays definite diagnoses andsimilarities in association with the respective thumbnail images.

In the example illustrated in FIG. 6, the maximum number of similarcases that can be displayed in the case display area 710 is 20. Themaximum number of similar cases that can be displayed is determined inadvance. The maximum number of similar cases that can be displayed mayalso be changed by the user as desired. If the number of similar casesreceived in S640 in FIG. 39 is larger than the maximum number of similarcases that can be displayed, the display control unit 104 displays thevertical scrollbar 715 at the right end of the case display area 710. Bymoving the scrollbar 715, the user is able to view the thumbnail imagesof similar cases that are not currently visible on the initial basicscreen K2.

Then, in S1300, a disease list is generated and displayed. First, adisease list is generated based on the similar cases received in S640 inFIG. 39. The disease list is a list in which the similar cases receivedin S640 are classified according to each definitely diagnosed diseasename.

It is assumed here that the number of similar cases received in S640 isrepresented by NC. The disease list management unit 108 generates adisease list by using the definite diagnosis (major-category diseasename) 4700 and the definite diagnosis (subcategory disease name) 4800registered in each of the NC pieces of similar case data 4000. Thegenerated disease list is managed by the disease list management unit108 as data in table format, as illustrated in FIG. 46.

FIG. 46 is a diagram illustrating the data configuration of the diseaselist generated in S1300 in FIG. 44. The disease list includes thefollowing fields: “disease ID”, “major-category disease name”,“subcategory disease name”, “number of results”, and “similar case ID”.The “disease ID” field represents an identifier assigned to eachdefinitely diagnosed disease name. Here, a disease ID is assigned to acombination of major-category and subcategory disease names.

The “major-category disease name” field represents a definitelydiagnosed disease name indicated by the definite diagnosis(major-category disease name) 4700 registered in the similar case data4000. The “subcategory disease name” field represents a name definitelydiagnosed disease indicated by the definite diagnosis (subcategorydisease name) 4800 registered in the similar case data 4000. The “numberof results” field represents the number of similar cases of thedefinitely diagnosed disease name identified by the “disease ID”. The“similar case ID” field represents a similar case ID that identifies asimilar case of the disease name identified by the “disease ID”.

The disease list management unit 108 extracts the definite diagnosis(major-category disease name) 4700 and the definite diagnosis(subcategory disease name) 4800 in each of the pieces of similar casedata 4000 received in S640, and classifies pieces of similar case data4000 having the same definite diagnosis (major-category disease name)4700 and the same definite diagnosis (subcategory disease name) 4800 aspieces of similar case data indicating similar cases of the samedefinitely diagnosed disease name. Further, the disease list managementunit 108 counts the number of similar cases of the same definitelydiagnosed disease name, and registers the number of similar cases in the“number of results” field of the record of the corresponding definitelydiagnosed disease name. The disease list management unit 108 alsoregisters the similar case IDs of the similar cases classified as thesame definitely diagnosed disease name in the “similar case ID” field ofthe record of the corresponding definitely diagnosed disease name.

In the example illustrated in FIG. 46, the disease ID “DIS528” isassigned to the definitely diagnosed disease name categorized as themajor-category disease name “neoplastic” and the subcategory diseasename “lung cancer”. The number of similar cases of this definitelydiagnosed disease name is 10. Thus, “10” is registered in the “number ofresults” field of the corresponding record, and the similar case IDs“SIM258”, “SIM551”, “SIM1209”, “SIM2341”, and so forth of the similarcases of the definitely diagnosed disease name are registered in the“similar case ID” field of the corresponding record.

The display control unit 104 generates the disease list display area 730by using the disease list generated in the way described above, anddisplays the disease list display area 730 on the display 101.

FIG. 47, FIG. 48, and FIG. 49 are diagrams illustrating a first exampledisplay, a second example display, and a third example display of thedisease list display area 730, respectively. As illustrated in FIG. 47,in the first example display, subcategory disease names are displayed inlist form in association with the numbers of similar cases thereof,which are obtained as a result of the similar case search, according tothe decreasing number of similar cases.

As illustrated in FIG. 48, in the second example display, major-categorydisease names are displayed in list form in association with the numbersof similar cases thereof, which are obtained as a result of the similarcase search, according to the decreasing number of similar cases.

As illustrated in FIG. 49, in the third example display, major-categorydisease names are displayed in list form in association with the numbersof similar cases thereof, which are obtained as a result of the similarcase search, according to the decreasing number of similar cases, andsubcategory disease names included in each of the major-category diseasenames are further displayed in list form in association with the numbersof similar cases thereof according to the decreasing number of similarcases. In this case, each definitely diagnosed disease name is expressedusing a hierarchical structure of a major-category disease name and asubcategory disease name.

FIG. 50 is a diagram illustrating a screen transition that occurs in thedisease list display area 730 illustrated in FIG. 48. As illustrated inthe upper part of FIG. 50, when the input control unit 103 detects theselection of a major-category disease name by the user among themajor-category disease names displayed in list form, as illustrated inthe lower part of FIG. 50, the display control unit 104 displays thesubcategory disease names that belong to the selected major-categorydisease name in association with the numbers of similar cases thereofaccording to the decreasing number of similar cases. In this case, theuser may select a desired major-category disease name from among, forexample, the major-category disease names displayed in list form in thedisease list display area 730 by, for example, double clicking or singleclicking. In the example illustrated in FIG. 50, “nonneoplastic” isdouble-clicked. Thus, subcategory disease names that belong to“nonneoplastic” are displayed in list form.

In the lower part of FIG. 50, when an area showing a list of subcategorydisease names is double-clicked or single-clicked by the user, thedisplay control unit 104 may hide the subcategory disease namesdisplayed in the area.

The display control unit 104 may determine subcategory disease namesthat belong to a major-category disease name by referring to the diseaselist (FIG. 46). For example, in the example illustrated in FIG. 46,aspergillosis and cryptococcosis are associated with mycosis. Thus, thedisplay control unit 104 may determine that aspergillosis andcryptococcosis belong to mycosis.

Referring back to FIG. 44, in S1400, a distribution list is generatedand displayed. First, a distribution list is generated based on thesimilar cases received in S640. The distribution list is a list in whichthe similar cases received in S640 are classified according to eachdistribution of lesions.

The disease list management unit 108 generates a distribution list byusing the distribution-of-lesion information 4600 registered in each ofthe NC pieces of similar case data 4000. The generated distribution listis managed by the distribution list management unit 109 as data in tableformat, as illustrated in FIG. 51.

FIG. 51 is a diagram illustrating the data configuration of thedistribution list generated in S1400 in FIG. 44. The distribution listincludes the following fields: “name of distribution”, “number ofcases”, and “similar case ID”. The “name of distribution” fieldrepresents the names of a plurality of predetermined distributions oflesions such as diffuse and segmental distributions. The “number ofcases” field represents the number of similar cases corresponding toeach distribution of lesions. The “similar case ID” field represents asimilar case ID that identifies a similar case corresponding to eachdistribution of lesions.

The distribution list management unit 109 extracts thedistribution-of-lesion information 4600 in each of the pieces of similarcase data 4000 received in S640, counts the number of distributions oflesions with the distribution flag value set to “1” (Applicable) in theextracted distribution-of-lesion information 4600, and registers thecount value in the “number of cases” field of the record of thecorresponding distribution of lesions. The distribution list managementunit 109 also registers the similar case IDs of the similar cases withthe distribution flag value set to “1” in the “similar case ID” field ofthe record of the corresponding distribution of lesions.

In the example illustrated in FIG. 51, the number of similar casescorresponding to the diffuse distribution is three. Thus, “3” isregistered in the “number of cases” field of the record of the diffusedistribution. Further, the similar case IDs “SIM2521”, “SIM4123”, and“SIM5225” of the similar cases corresponding to the diffuse distributionare registered in the “similar case ID” field of the record of thediffuse distribution.

The display control unit 104 generates the distribution list displayarea 750 by using the distribution list generated in the way describedabove, and displays the distribution list display area 750 on thedisplay 101.

FIG. 52 is a diagram illustrating the distribution list display area 750generated using the distribution list illustrated in FIG. 51. In FIG.51, the number of cases corresponding to the segmental and subpleuraldistributions is 0. Accordingly, the “segmental” 752 and the“subpleural” 756 are displayed as inactive in FIG. 52. The number ofcases corresponding to the other distributions of lesions is greaterthan or equal to one, and such distributions of lesions are displayed asactive accordingly.

Referring back to FIG. 44, in S1500, the layout area 720 is displayed.This process is performed by the display control unit 104.

FIG. 45 is a flowchart illustrating the processing of S1500 illustratedin FIG. 44. In S1510, the display control unit 104 obtains the number ofrows and columns of display boxes in the layout area 720 from thedisplay box management information 4410 set in S660. In the example ofthe display box management information 4410 illustrated in FIG. 40, thenumber of rows and the number of columns are set to two and two,respectively, and information indicating “two rows and two columns” isobtained. If a user changes the number of rows and columns of displayboxes, the number of rows and columns of display boxes in the layoutarea 720 is obtained from the layout management information 4200illustrated in FIG. 42 or FIG. 43.

Then, in S1520, the display control unit 104 draws display boxes inaccordance with the number of rows and columns obtained in S1510.

Finally, in S1530, the display control unit 104 identifies a slice IDfor each display box from the display box management information 4410,and draws a thumbnail image corresponding to the identified slice ID inthe corresponding one of the display boxes.

In the example illustrated in FIG. 40, the slice ID of the case to bediagnosed is stored in the display box in the first row and the firstcolumn. Accordingly, the display control unit 104 generates a thumbnailimage from the slice image of the case to be diagnosed, which istransmitted in S600 in FIG. 35, and draws the generated thumbnail imagein the display box 721.

In this stage, no slice IDs are stored in the other display boxes (i.e.,the display boxes 722, 723, and 724 in the first row and the secondcolumn, the second row and the first column, the second row and thesecond column, respectively). Thus, the display control unit 104displays no images in these display boxes. A thumbnail image of asimilar case is displayed in these display boxes through a processdescribed below.

Referring back to FIG. 39, the communication control unit 110 transmitsthe display box management information 4410 stored in the display boxmanagement unit 106 to the display control unit 104 (S680).

Then, the display control unit 104 starts a medical image viewer in thesame display state and layout as the display state and layout of thelayout area 720 (S690).

In the illustrated example, the case search system 300 extracts an imagefeature. Alternatively, the information terminal 100 may extract animage feature. FIG. 53 is a block diagram of the information terminal100, the medical information management system 200, and the case searchsystem 300 according to an embodiment in which the case search system300 extracts an image feature.

The configuration illustrated in FIG. 53 is different from thatillustrated in FIG. 2 in that the information terminal 100 furtherincludes an image feature extraction unit 113 and the case search system300 does not include the image feature extraction unit 302.

FIG. 54 is a sequence diagram illustrating a process performed during aperiod in which, after the information terminal 100 obtains a case to bediagnosed from the medical information management system 200, the casesearch system 300 receives a similar case search request.

The operation illustrated in FIG. 54 is different from that illustratedin FIG. 35 in that, after the ROI management unit 105 transmits a sliceimage of the case to be diagnosed to the communication control unit 110(S600), the information terminal 100 extracts an image feature (S603)and transmits the extracted image feature to the case search system 300(S604). The process for extracting an image feature (S603) is similar tothat in the case where the case search system 300 extracts an imagefeature.

FIG. 55 is a sequence diagram illustrating a process performed during aperiod in which, after receiving the similar case search request, thecase search system 300 returns similar case search results to theinformation terminal 100. The operation illustrated in FIG. 55 isdifferent from that illustrated in FIG. 39 in that, since an imagefeature is extracted by the information terminal 100, the extraction ofan image feature (S610) in FIG. 39 is omitted in FIG. 55.

Next, the process for enlarging the thumbnail images displayed in thecase display area 710, which has been described with reference to FIG. 8to FIG. 11, will be described.

FIG. 56 is a flowchart illustrating a process for enlarging thethumbnail images displayed in the case display area 710.

In S4000, the enlarged image generation unit 112 obtains the similarcase ID 4100 (FIG. 33) of the thumbnail image selected by the user (inFIG. 8, the thumbnail image in the first row and the fourth column). Inthe following, the thumbnail image selected by the user is referred toas the “reference thumbnail image”. The enlarged image generation unit112 determines enlargement factors for the other thumbnail imagesdisplayed in the case display area 710, in association with anenlargement operation performed on the reference thumbnail image by theuser.

In S4100, the enlarged image generation unit 112 obtains, from the inputcontrol unit 103, the amount of enlargement operation performed on thereference thumbnail image, which is input to the operation unit 102 bythe user. Then, the enlarged image generation unit 112 determines anenlargement factor for the reference thumbnail image on the basis of theobtained amount of operation.

Specifically, the input control unit 103 detects the amount of rotationof the mouse wheel, which is input to the operation unit 102 as anenlargement operation. The input control unit 103 notifies the enlargedimage generation unit 112 of the detected amount of rotation. Theenlarged image generation unit 112 multiplies the amount of rotation bya predetermined coefficient to calculate an enlargement factor for thereference thumbnail image.

As described above, the user may perform an enlargement operation byusing the up arrow key or the down arrow key on the keyboard. In thiscase, the input control unit 103 may detect the length of time duringwhich the key is pressed. The enlarged image generation unit 112 maymultiply the length of time during which the key is pressed by apredetermined coefficient to calculate an enlargement factor for thereference thumbnail image.

In S4200, the enlarged image generation unit 112 determines a targetsimilar case to be subjected to an enlargement process among a largenumber of similar cases obtained from the case search system 300. Asillustrated in FIG. 6, the display control unit 104 displays, in thecase display area 710, thumbnail images of similar cases, the number ofwhich is equal to the predetermined maximum number ND (in thisembodiment, ND=20) of results allowed to be displayed in the casedisplay area 710, among NC (in FIG. 6, NC=62) pieces of similar casedata found as a result of the search by the similar case search unit 303of the case search system 300.

In this step, the enlarged image generation unit 112 determines a targetsimilar case to be subjected to an enlargement process within a rangeless than or equal to ND so that thumbnail image selected by the user isincluded. In this embodiment, the enlarged image generation unit 112determines NZ target similar cases to be subjected to an enlargementprocess, where NZ≤ND. This step may reduce the processing load on theinformation terminal 100, compared to the case where the thumbnail imageof all the NC similar cases are enlarged.

In S4300, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. Then, the enlarged imagegeneration unit 112 repeatedly performs the processing of S4400 andS4500 until the index i has reached NZ (YES in S4300). The enlargedimage generation unit 112 increments the index i by 1 each time theprocessing of S4400 and S4500 is executed. If the index i exceeds NZ (NOin S4300), the process illustrated in FIG. 56 ends.

In S4400, the enlarged image generation unit 112 calculates anenlargement factor for the thumbnail image of the similar case i to besubjected to enlargement. The enlarged image generation unit 112calculates an enlargement factor for the similar case i to be subjectedto enlargement, on the basis of the enlargement factor for the referencethumbnail image, which is determined in S4100, the region-of-interestinformation 4300 (FIG. 33) on the similar case corresponding to thereference thumbnail image, and the region-of-interest information 4300(FIG. 33) on the similar case i to be subjected to enlargement.

FIG. 57 is a flowchart illustrating a process in a subroutine of S4400in FIG. 56.

In S4410, the enlarged image generation unit 112 calculates the area ofthe region of interest in the reference thumbnail image on the basis ofthe region-of-interest information 4300 on the similar casecorresponding to the reference thumbnail image. Given that the area ofthe region of interest in the reference thumbnail image is representedby Sr, the coordinates of the upper left corner of the region ofinterest are represented by (xl, yt), and the coordinates of the lowerright corner of the region of interest are represented by (xr, yb), thearea Sr of the region of interest can be calculated in accordance withthe following equation:Sr=|xl−xr|×|yt−yb|.

In S4420, the enlarged image generation unit 112 calculates the area ofthe region of interest in the thumbnail image of the similar case i tobe subjected to enlargement, on the basis of the region-of-interestinformation 4300 on the similar case i to be subjected to enlargement.Given that the area of the region of interest in the thumbnail image ofthe similar case i to be subjected to enlargement is represented by Si,the coordinates of the upper left corner of the region of interest arerepresented by (xli, yti), and the coordinates of the lower right cornerof the region of interest are represented by (xri, ybi), the area Si ofthe region of interest can be calculated in accordance with thefollowing equation:Si=|xli−xri|×|yti−ybi|.

In S4430, the enlarged image generation unit 112 calculates anenlargement factor for the similar case i to be subjected toenlargement, on the basis of the area Sr of the region of interest inthe reference thumbnail image, which is calculated in S4410, the area Siof the region of interest in the thumbnail image of the similar case ito be subjected to enlargement, which is calculated in S4420, and theenlargement factor for the reference thumbnail image, which isdetermined in S4100. Given that the enlargement factor for the referencethumbnail image is represented by kr, the enlargement factor ki for thesimilar case i to be subjected to enlargement can be calculated inaccordance with the following equation:ki=kr(Sr/Si).

FIG. 58 is a diagram schematically illustrating reference thumbnailimages obtained before and after an enlargement process is performed andenlargement-intended thumbnail images obtained before and after anenlargement process is performed. The upper left part of FIG. 58illustrates the reference thumbnail image obtained before theenlargement process is performed. The upper right part of FIG. 58illustrates the reference thumbnail image obtained after the enlargementprocess is performed. The lower left part of FIG. 58 illustrates theenlargement-intended thumbnail image obtained before the enlargementprocess is performed. The lower right part of FIG. 58 illustrates theenlargement-intended thumbnail image obtained after the enlargementprocess is performed.

As a result of enlarging the reference thumbnail image illustrated inthe upper left part of FIG. 58 with the enlargement factor kr, thethumbnail image illustrated in the upper right part of FIG. 58 isobtained. The enlarged image generation unit 112 determines a displayarea 720 d so that, in the upper right part of FIG. 58, the position ofthe center of the region of interest ROI matches the position of thecenter of the display area 720 d. The enlarged image generation unit 112performs enlargement so that the size of the display area 720 d ismaintained to be equal to the size of a display area 720 c before theenlargement process is performed.

As a result of enlarging the enlargement-intended thumbnail imageillustrated in the lower left part of FIG. 58 with the enlargementfactor ki, the thumbnail image illustrated in the lower right part ofFIG. 58 is obtained. The enlarged image generation unit 112 determines adisplay area 720 f so that, in the lower right part of FIG. 58, theposition of the center of the region of interest ROI matches theposition of the center of the display area 720 f. The enlarged imagegeneration unit 112 performs enlargement so that the size of the displayarea 720 f is maintained to be equal to the size of a display area 720 ebefore the enlargement process is performed.

In FIG. 58, the enlargement factor ki for the enlargement-intendedthumbnail image i with respect to the enlargement factor kr for thereference thumbnail image is determined in accordance with the arearatio of the regions of interest. Accordingly, as illustrated in FIG.58, the sizes of the regions of interest ROI after enlargement match.

Referring back to FIG. 56, in S4500, the enlarged image generation unit112 generates an enlarged thumbnail image of the similar case i to besubjected to enlargement, on the basis of the enlargement factorcalculated in S4400 and the region-of-interest information 4300 and thethumbnail image data 4500 in the similar case data 4000 (FIG. 33). Thedisplay control unit 104 displays the thumbnail image generated by theenlarged image generation unit 112.

FIG. 59 is a flowchart illustrating a process in a subroutine of S4500in FIG. 56. FIG. 60 is a diagram schematically illustrating therelationship between an enlargement factor and a display area. Theprocess for generating an enlarged image so that the position of thecenter of the region of interest matches the position of the center ofan enlarged thumbnail image will now be described in detail withreference to FIG. 59 and FIG. 60.

In S4510, the enlarged image generation unit 112 generates an enlargedimage on the basis of the enlargement factor calculated in S4400 and thethumbnail image data 4500 in the similar case data 4000 (FIG. 33). Ifthe enlargement factor is ki, an enlarged thumbnail image illustrated inthe right part of FIG. 60 is generated from a thumbnail imageillustrated in the left part of FIG. 60.

In S4520, the enlarged image generation unit 112 calculates thecoordinates of the center of the region of interest in the enlargedthumbnail image, on the basis of the region-of-interest information 4300in the similar case data 4000 (FIG. 33) and the enlargement factorcalculated in S4400. Given that the coordinates of the center of theregion of interest before enlargement is represented by (xc, yc), asillustrated in FIG. 60, coordinates (ki×xc, ki×yc), which are obtainedby multiplying the coordinates of the center of the region of interestbefore enlargement by the enlargement factor, are the coordinates of thecenter of the region of interest after enlargement.

In S4530, the enlarged image generation unit 112 determines a displayarea in the enlarged thumbnail image i by using the coordinates (ki×xc,ki×yc) of the center of the region of interest after enlargement, whichare calculated in S4520, and a predetermined size of the display area.As illustrated in the left part of FIG. 60, a display area 720 a is setto have a width dimension w and a height dimension h. In this case, arectangular area illustrated in the right part of FIG. 60 corresponds toa display area 720 b. The display area 720 b has upper left coordinatesgiven by (ki×xc−w/2, ki×yc−h/2), and lower right coordinates given by(ki×xc+w/2, ki×yc+h/2).

In S4540, the display control unit 104 displays, in the display area ofthe similar case i within the case display area 710, an image of thedisplay area 720 b calculated in S4530 within the enlarged imagegenerated in S4510 by the enlarged image generation unit 112. Throughthe process illustrated in FIG. 59, an enlarged thumbnail image i can begenerated in such a manner that the position of the center of the regionof interest coincides with the position of the center of the center ofthe display area.

Through the process described above, thumbnail images are displayed inthe case display area 710 with an arbitrary enlargement factor specifiedby the user. In response to an enlargement operation performed on asingle thumbnail image by the user, the enlargement factors for all thethumbnail images in the case display area 710 can be changed. This mayreduce the operation load on the user. In addition, the thumbnail imagesare displayed in the case display area 710 in such a manner that thesizes of the regions of interest are uniform. This may prevent theoccurrence of oversight caused by the way in which the region ofinterest in some similar medical images has been enlarged but is small,and may improve diagnosis accuracy. In addition, not all the similarcases obtained as a result of the similar case search but similar casesdisplayed in the case display area 710 are subjected to an enlargementprocess, resulting in a significantly reduced load on a system.

Next, a process performed during a period in which, after thumbnailimages obtained as a result of the similar case search are enlarged anddisplayed on the information terminal 100, a display area of a thumbnailimage is changed in response to a user operation will be described.

FIG. 61 is a sequence diagram illustrating a process performed during aperiod in which, after thumbnail images obtained as a result of thesimilar case search are enlarged and displayed on the display 101 b ofthe information terminal 100, a display area is changed.

First, the input control unit 103 of the information terminal 100detects that the user has selected a thumbnail image by operating theoperation unit 102 (e.g., by operating the left button of the mouse)(S5000).

Then, when the user performs a (drag) operation of changing the mouseposition, the input control unit 103 detects the amount of movement ofthe mouse, and notifies the enlarged image generation unit 112 of thedetected amount of movement of the mouse (S5100).

Then, the enlarged image generation unit 112 determines an amount ofmovement of a display area in a thumbnail image by using the detectedamount of movement of the mouse, and generates a thumbnail image inwhich the display area has moved the determined amount (S5200).

Then, the display control unit 104 displays the thumbnail imagegenerated by the enlarged image generation unit 112 in the case displayarea 710 (S5300).

The details of the processing of S5200 described above will now bedescribed. The processing of S5200 is performed by the enlarged imagegeneration unit 112. In the following, first, the details of theprocessing blocks of the enlarged image generation unit 112 will bedescribed, and then the flow of the display area changing process willbe described.

FIG. 62 is a block diagram illustrating the detailed configuration ofthe enlarged image generation unit 112. The enlarged image generationunit 112 includes an input determination unit 1121, a referenceenlargement factor determination unit 1122, a target determination unit1123, an enlargement factor determination unit 1124, an imageenlargement unit 1125, a first display area determination unit 1126, anamount-of-movement determination unit 1127, a display image generationunit 1129, and a second display area determination unit 1128. Theenlarged image generation unit 112 performs an enlargement factorchanging process and a display area changing process. In the following,the individual units of the enlarged image generation unit 112 will bedescribed.

The input determination unit 1121 determines the content of theoperation performed on the operation unit 102 by a user, of which theenlarged image generation unit 112 is notified by the input control unit103. If the determined content of the operation indicates an enlargementfactor changing operation (e.g., the rotation of the mouse wheel), theinput determination unit 1121 outputs the amount of operation (theamount of rotation of the wheel) and the type of the operation (therotation of the mouse wheel) to the reference enlargement factordetermination unit 1122. The input determination unit 1121 furtheroutputs operation content information to the target determination unit1123 and the enlargement factor determination unit 1124. The operationcontent information to be output is information indicating a change ofthe enlargement factor. For example, the value “1” preset as a valuecorresponding to information indicating a change of the enlargementfactor is output from the input determination unit 1121 to the targetdetermination unit 1123 and the enlargement factor determination unit1124.

Note that the content of the operation of which the enlarged imagegeneration unit 112 is notified by the input control unit 103 as theenlargement factor changing operation is not limited to the operation ofrotating the mouse wheel. For example, as described above, the up arrowkey or down arrow key on the keyboard may be operated. In this case, theinput control unit 103 may count the length of time during which the uparrow key or the down arrow key is pressed. The input determination unit1121 may use the length of time during which the up arrow key or thedown arrow key is pressed as the amount of operation.

If the determined content of the operation indicates a display areachanging operation (e.g., mouse dragging), the input determination unit1121 outputs the amount of operation (e.g., the start position and endposition of mouse dragging) to the amount-of-movement determination unit1127. The input determination unit 1121 further outputs operationcontent information to the target determination unit 1123. The operationcontent information to be output is information indicating a change of adisplay area. For example, the value “2” preset as a value correspondingto information indicating a change of a display area is output from theinput determination unit 1121 to the target determination unit 1123.

Note that the content of the operation of which the enlarged imagegeneration unit 112 is notified by the input control unit 103 as thedisplay area changing operation is not limited to mouse dragging. Forexample, a control button and an arrow key on the keyboard may beconcurrently operated. In this case, the input control unit 103 maycount the length of time during which the control button and the arrowkey are pressed. The input determination unit 1121 may use the length oftime during which the control button and the arrow key are pressed asthe amount of operation. The input determination unit 1121 may furtherdetermine the direction corresponding to the operated arrow key as amovement direction.

If the determined content of the operation indicates the selection of adistribution of lesions (checking the checkbox for the distribution listdisplay area 750), the input determination unit 1121 outputs theinformation indicating the selected distribution of lesions to theenlargement factor determination unit 1124. The input determination unit1121 further outputs operation content information to the targetdetermination unit 1123. The operation content information to be outputis information indicating a change of the enlargement factor in responseto the selection of a distribution of lesions. For example, the value“3” preset as a value corresponding to information indicating a changeof the enlargement factor in response to the selection of a distributionof lesions is output from the input determination unit 1121 to thetarget determination unit 1123.

Note that the information output from the input determination unit 1121to the enlargement factor determination unit 1124 is not limited to theinformation indicating the selected distribution of lesions. Asdescribed below, the distributions of lesions are separated into firstdistribution information, second distribution information, and thirddistribution information. Thus, the input determination unit 1121 mayoutput distribution information (the first distribution information, thesecond distribution information, or the third distribution information)to which the selected distribution of lesions belongs to the enlargementfactor determination unit 1124.

The reference enlargement factor determination unit 1122 determines anenlargement factor for the thumbnail image selected by the user. Asdescribed above, the amount and type of operation performed by the userusing the operation unit 102 are output to the reference enlargementfactor determination unit 1122 from the input determination unit 1121.The reference enlargement factor determination unit 1122 obtains, fromthe input control unit 103, information indicating the area selected bythe user (e.g., in FIG. 12, the thumbnail image in the second row andthe fourth column). The reference enlargement factor determination unit1122 obtains the similar case ID 4100 with reference to the similar casedata 4000 (FIG. 33) of the thumbnail image selected by the user.

If the operation type is the rotation of the mouse wheel, the referenceenlargement factor determination unit 1122 obtains the amount ofrotation of the wheel as the amount of operation. If the type ofoperation is an arrow key on the keyboard, the reference enlargementfactor determination unit 1122 obtains the length of time during whichthe arrow key is pressed as the amount of operation. The referenceenlargement factor determination unit 1122 calculates a value bymultiplying the amount of operation by a predetermined coefficient, anddetermines the calculated value as an enlargement factor for thereference thumbnail image. The reference enlargement factordetermination unit 1122 outputs the similar case ID 4100 and thedetermined enlargement factor to the enlargement factor determinationunit 1124.

The target determination unit 1123 determines a similar case to besubjected to a thumbnail image enlargement process or a display areachanging process, on the basis of the operation content informationinput from the input determination unit 1121.

If the operation content information is information indicating a changeof the enlargement factor, the target determination unit 1123 obtains,from the input control unit 103, information indicating the areaselected by the user (e.g., in FIG. 12, the thumbnail image in thesecond row and the fourth column). The target determination unit 1123obtains the similar case ID 4100 with reference to the similar case data4000 (FIG. 33) of the thumbnail image selected by the user. The targetdetermination unit 1123 determines similar cases, the number of which isless than or equal to ND, as targets to be subjected to enlargement sothat the thumbnail image selected by the user is included. The targetdetermination unit 1123 outputs the number of similar cases and thesimilar case IDs 4100 of the similar cases to the enlargement factordetermination unit 1124.

If the operation content information is information indicating a changeof a display area, the target determination unit 1123 uses the similarcase to be subjected to enlargement, which is determined in theenlargement factor changing process, directly as a target to besubjected to the display area changing process.

If the operation content information is information indicating a changeof the enlargement factor in response to the selection of a distributionof lesions, the target determination unit 1123 outputs the similar caseIDs 4100 obtained as a result of refinement in accordance with aselected distribution of lesions and the number of similar case IDs 4100to the enlargement factor determination unit 1124.

The enlargement factor determination unit 1124 determines an enlargementfactor for the similar cases that are targets of enlargement, which aredetermined by the target determination unit 1123. If informationindicating the selected distribution of lesions is input from the inputdetermination unit 1121 as operation content information, theenlargement factor determination unit 1124 calculates a predeterminedenlargement factor corresponding to the selected distribution oflesions. The enlargement factor determination unit 1124 outputs thedetermined enlargement factor, and the similar case IDs 4100 of thetargets of enlargement and the number of similar case IDs, which areinput from the target determination unit 1123, to the image enlargementunit 1125. Predetermined enlargement factors corresponding to therespective distributions of lesions are as described above withreference to FIG. 21 to FIG. 26.

If information indicating a change of the enlargement factor is inputfrom the input determination unit 1121 as operation content information,the enlargement factor determination unit 1124 extracts theregion-of-interest information 4300 corresponding to the similar caseIDs 4100 (FIG. 33) of the targets of enlargement, which are input fromthe target determination unit 1123. The enlargement factor determinationunit 1124 calculates enlargement factors for the respective similarcases by using the extracted region-of-interest information 4300 and theenlargement factor for the reference thumbnail image, which is inputfrom the reference enlargement factor determination unit 1122, throughthe procedure described above with reference to FIG. 57. The enlargementfactor determination unit 1124 outputs the calculated enlargementfactors, the similar case IDs 4100 of the targets of enlargement, andthe number of similar case IDs to the image enlargement unit 1125.

The image enlargement unit 1125 generates thumbnail images, which areobtained by enlarging the thumbnail images of the input similar case IDs4100, by using the enlargement factors input from the enlargement factordetermination unit 1124, the similar case IDs 4100 of the targets ofenlargement, and the number of similar case IDs. The image enlargementunit 1125 outputs the generated enlarged thumbnail images to the displayimage generation unit 1129.

The first display area determination unit 1126 determines a display areain an enlarged thumbnail image of a similar case that is a target ofenlargement. The first display area determination unit 1126 extracts theregion-of-interest information 4300 corresponding to the similar case ID4100 (FIG. 33) of the target of enlargement, which is input from theenlargement factor determination unit 1124. The first display areadetermination unit 1126 calculates the coordinates of the display areain the enlarged thumbnail image by using the enlargement factor inputfrom the enlargement factor determination unit 1124 and the extractedregion-of-interest information 4300 through the process described abovein S4520 and S4530 in FIG. 59. The first display area determination unit1126 outputs the similar case ID 4100 of the target of enlargement andthe coordinates of the corresponding display area to the display imagegeneration unit 1129 and the second display area determination unit1128.

The amount-of-movement determination unit 1127 determines the amount ofmovement of the display area in the enlarged thumbnail image. Theamount-of-movement determination unit 1127 calculates a value bymultiplying the amount of operation input from the input determinationunit 1121 (e.g., the start position and end position of mouse dragging)by a predetermined coefficient, and determines the calculated value asthe amount of movement of display area in the enlarged thumbnail image.

For example, it is assumed that the operation performed on the operationunit 102 by the user is mouse dragging. In addition, the x-directioncoefficient is defined as “a”, the y-direction coefficient is defined as“b”, the drag start position is defined as “ps(xs, ys)”, and the dragend position is defined as “pe(xe, ye)”. In this case, the amount ofmovement d is given by the following expression:d(a(xe−xs),b(ye−ys)).

The amount-of-movement determination unit 1127 outputs the calculatedamount of movement to the second display area determination unit 1128.

FIG. 63 is a diagram schematically illustrating the movement of adisplay area across an enlarged thumbnail image. The left part of FIG.63 corresponds to the right part of FIG. 60, and illustrates an enlargedthumbnail image. The right part of FIG. 63 illustrates the display areathat has moved from the state illustrated in the left part of FIG. 63.

In the left part of FIG. 63, the coordinates of the center of a displayarea A631 in the enlarged thumbnail image is given by the followingexpression:(ki×xd,ki×yd).

In a case where the display area in the enlarged thumbnail image movesthe amount of movement d from the state illustrated in the left part ofFIG. 63, the coordinates of the center of a display area A632 that hasmoved, which is illustrated in the right part of FIG. 63, is given bythe following expression:(ki×xd+a(xe−xs),ki×yd+b(ye−ys)).

In this case, the display areas A631 and A632 have the same size, andthe position of the display area has been changed in the enlargedthumbnail image.

Referring back to FIG. 62, the second display area determination unit1128 determines a display area in a thumbnail image of a similar casewhen the display area moves. The second display area determination unit1128 determines the coordinates of a display area that has moved, byusing the amount of movement input from the amount-of-movementdetermination unit 1127 and the display area corresponding to thesimilar case ID 4100 of the target of enlargement, which is input fromthe first display area determination unit 1126. The second display areadetermination unit 1128 outputs the determined coordinates of thedisplay area to the display image generation unit 1129.

If the information input from the image enlargement unit 1125, the firstdisplay area determination unit 1126, and the second display areadetermination unit 1128 includes a change in a display image, thedisplay image generation unit 1129 updates the display image.

Specifically, the display image generation unit 1129 generates, as anenlarged thumbnail image, an area defined by the coordinates of thedisplay area, which are input from the first display area determinationunit 1126 or the second display area determination unit 1128, within anenlarged thumbnail image of the similar case to be subjected toenlargement, which is input from the image enlargement unit 1125. Thedisplay image generation unit 1129 outputs the generated thumbnail imageto the display control unit 104.

As described above, in a case where the enlargement factor is changed inresponse to the selection of a distribution of lesions, if the“bilateral” 754 is selected (FIG. 21), the entire thumbnail images aredisplayed with an enlargement factor of 1.0 (FIG. 22). Thus, the displayareas are not changed. The same applies when the “diffuse” 751, the“multiple” 755, or the “hematogenous” 757 is selected in FIG. 20. The“diffuse”, “bilateral”, “multiple”, and “hematogenous” lesiondistributions belong to the first distribution information (describedbelow). That is, when a distribution of lesions that belongs to thefirst distribution information is selected, the entire thumbnail imagesare displayed with an enlargement factor of 1.0, and the display areasare not changed.

Accordingly, in a case where the enlargement factor is changed inresponse to the selection of a distribution of lesions that belongs tothe first distribution information, the input determination unit 1121may not necessarily output the amount of operation to theamount-of-movement determination unit 1127 even if the determinedcontent of the operation indicates a display area changing operation.Alternatively, the target determination unit 1123 may determine thatnone of the similar cases is set as a target to be subjected to adisplay area changing process.

Next, the flow of a process for changing a display area for an enlargedthumbnail image will be described.

FIG. 64 is a flowchart illustrating a process for changing a displayarea for an enlarged thumbnail image. In S6000, the input determinationunit 1121 obtains, from the input control unit 103, the content of theoperation performed on the operation unit 102 by the user and the amountof the operation.

In S6100, the input determination unit 1121 determines the content ofthe operation obtained in S6000. If the determined content of theoperation indicates an enlargement factor changing operation, theprocess proceeds to, for example, the enlargement process illustrated inFIG. 56. If the determined content of the operation indicates theselection of a distribution of lesions, the process proceeds to, forexample, a process illustrated in FIG. 71 (described below). If thedetermined content of the operation indicates a display area changingoperation, the process proceeds to S6200.

In S6200, the target determination unit 1123 obtains a similar case tomove on which a display area changing process is to be performed. Inthis embodiment, the target determination unit 1123 uses, as a similarcase to move, a similar case for which the enlargement factor has beenchanged in the enlargement factor changing process in S6200. When thedisplay area changing process is performed, thumbnail images of similarcases, the number of which is equal to NZ less than or equal to themaximum number ND of similar cases allowed to be displayed in the casedisplay area 710 (in this embodiment, ND=20), among the NC similar casesreceived from the similar case search unit 303 are enlarged anddisplayed in the case display area 710. In the example illustrated inFIG. 12, 20 thumbnail images are enlarged and displayed.

In S6300, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. Then, the enlarged imagegeneration unit 112 repeatedly performs the processing of S6400 to S6700until the index i has reached NZ (YES in S6300). The enlarged imagegeneration unit 112 increments the index i by 1 each time the processingof S6400 to S6700 is executed. If the index i exceeds NZ (NO in S6300),the process illustrated in FIG. 64 ends.

In S6400, the amount-of-movement determination unit 1127 calculates theamount of movement of the thumbnail image of the similar case i to beprocessed. The amount-of-movement determination unit 1127 calculates avalue by multiplying the amount of operation input from the inputdetermination unit 1121 by a predetermined coefficient, and determinesthe calculated value as the amount of movement of the display area.

In S6500, the second display area determination unit 1128 determines adisplay area that has been changed in the thumbnail image, by using thedisplay area determined in S4530 (FIG. 59) and the amount of movementdetermined in S6400. In S6600, the display image generation unit 1129obtains the enlarged image generated in S4510 (FIG. 59). In S6700, thedisplay image generation unit 1129 generates a display image by usingthe display area determined in S6500 and the enlarged image obtained inS6600.

As described above, if a distribution of lesions that belongs to thefirst distribution information is selected, the display area is notchanged. Accordingly, in a case where the enlargement factor has beenchanged in response to the selection of a distribution of lesions thatbelongs to the first distribution information, then in S6200, the targetdetermination unit 1123 may determine that none of the similar cases isset as a target to be subjected to a display area changing process, andthe process may end. Alternatively, in S6200, the target determinationunit 1123 may set the index i to a value exceeding NZ, and may obtain anegative determination in S6300.

The configuration of the enlarged image generation unit 112 thatperforms a display area changing process is not limited to theconfiguration illustrated in FIG. 62. Next, a modification of thedisplay area changing process will be described. In the following,first, the details of the processing blocks of the enlarged imagegeneration unit 112 will be described, and then the flow of the displayarea changing process will be described.

FIG. 65 is a block diagram illustrating a detailed configuration of theenlarged image generation unit 112, which is different from thatillustrated in FIG. 62. The enlarged image generation unit 112 includesthe input determination unit 1121, the reference enlargement factordetermination unit 1122, the target determination unit 1123, theenlargement factor determination unit 1124, an amount-of-movementdetermination unit 1130, a display area determination unit 1131, and animage enlargement unit 1132. In FIG. 65, substantially the same blocksas those in FIG. 62 are assigned the same numerals, and are notdescribed in detail herein.

The amount-of-movement determination unit 1130 obtains the enlargementfactor for the reference thumbnail image from the reference enlargementfactor determination unit 1122. The amount-of-movement determinationunit 1130 obtains the determined enlargement factors for the respectivethumbnail images from the enlargement factor determination unit 1124.The amount-of-movement determination unit 1130 obtains the amount ofoperation from the input determination unit 1121. The amount-of-movementdetermination unit 1130 calculates the amount of movement in thethumbnail image before enlargement, by using the enlargement factors forthe respective thumbnail images and the amount of operation. Theamount-of-movement determination unit 1130 outputs the calculated amountof movement and the enlargement factors for the respective thumbnailimages to the display area determination unit 1131.

Similarly to the first display area determination unit 1126, the displayarea determination unit 1131 determines a display area in the enlargedthumbnail image of the similar case that is a target of enlargement.That is, the display area determination unit 1131 obtains the similarcase ID 4100 (FIG. 33) of the target of enlargement from the enlargementfactor determination unit 1124. The display area determination unit 1131extracts the region-of-interest information 4300 corresponding to theobtained similar case ID 4100 (FIG. 33) of the target of enlargement.The display area determination unit 1131 calculates the coordinates ofthe display area in the enlarged thumbnail image by using theenlargement factor input from the enlargement factor determination unit1124 and the extracted region-of-interest information 4300 through theprocedure described above with reference to S4520 and S4530 in FIG. 59.

The display area determination unit 1131 obtains the enlargement factorfor the reference thumbnail image from the reference enlargement factordetermination unit 1122. The display area determination unit 1131obtains the enlargement factors for the respective thumbnail images fromthe enlargement factor determination unit 1124. The display areadetermination unit 1131 obtains the amount of movement in the thumbnailimage before enlargement from the amount-of-movement determination unit1130. The display area determination unit 1131 calculates thecoordinates of the display area in the thumbnail image beforeenlargement before the display area has moved, by using the calculatedcoordinates of the display area in the enlarged thumbnail image and theacquired enlargement factors.

The display area determination unit 1131 adds the obtained amount ofmovement in the thumbnail image before enlargement to the calculatedcoordinates of the display area in the thumbnail image beforeenlargement before the display area has moved to calculate thecoordinates of the display area in the thumbnail image beforeenlargement after display area has moved. The display area determinationunit 1131 outputs the calculated coordinates of the display area in thethumbnail image before enlargement after display area has moved to theimage enlargement unit 1132.

The image enlargement unit 1132 obtains the enlargement factor for thereference thumbnail image from the reference enlargement factordetermination unit 1122. The image enlargement unit 1132 obtains theenlargement factors for the respective thumbnail images from theenlargement factor determination unit 1124. The image enlargement unit1132 enlarges thumbnail images in the display area, by using thecoordinates of the display area in the thumbnail image beforeenlargement after display area has moved, which are input from thedisplay area determination unit 1131, and the obtained enlargementfactors for the respective thumbnail images. The image enlargement unit1132 outputs the generated enlarged thumbnail images to the displaycontrol unit 104.

FIG. 66 is a flowchart illustrating a display area changing processperformed using the configuration illustrated in FIG. 65. FIG. 67A is adiagram illustrating an example of an enlarged thumbnail image. FIG. 67Bis a diagram illustrating an entire thumbnail image before the thumbnailimage illustrated in FIG. 67A is enlarged. FIG. 67C is a diagramschematically illustrating the movement of a display area across thethumbnail image before enlargement. In FIG. 66, substantially the samesteps as those illustrated in FIG. 64 are assigned the same numerals,and are not described in detail herein.

In S6800, the amount-of-movement determination unit 1130 calculates theamount of movement in the thumbnail image before enlargement, by usingthe obtained amount of operation and the enlargement factors for therespective thumbnail images.

For example, it is assumed that the operation performed on the operationunit 102 by the user is mouse dragging. In addition, the x-directioncoefficient is defined as “a”, the y-direction coefficient is defined as“b”, the drag start position is defined as “ps(xs, ys)”, and the dragend position is defined as “pe(xe, ye)”. In this case, when the positionof the display area is moved, the amount of movement da in an enlargedthumbnail image in the x-direction and y-direction is given by thefollowing equation:da=(a(xe−xs),b(ye−ys)).

The amount of movement db in a thumbnail image before enlargement in thex-direction and y-direction is given by the following equation:db=(a(xe−xs)/ki,b(ye−ys)/ki).

In S6900, the display area determination unit 1131 adds the amount ofmovement in the thumbnail image before enlargement, which is input fromthe amount-of-movement determination unit 1130, to the calculatedcoordinates of the display area in the thumbnail image beforeenlargement before the display area has moved to calculate thecoordinates of the display area in the thumbnail image beforeenlargement after display area has moved.

As illustrated in FIG. 67A, the center of the display area in theenlarged thumbnail image is defined as (xdp, ydp), and the enlargementfactor for the thumbnail image is defined as ki. In this case, thecoordinates of the center C67B in the thumbnail image beforeenlargement, which is illustrated in FIG. 67B, is given by the followingexpression:(xdp/ki,ydp/ki).

The coordinates of the center C67C of the display area in the thumbnailimage before enlargement after the user has performed a movementoperation, which is illustrated in the left part of FIG. 67C, is givenby the following expression by using the amount of movement db describedabove:(xdp/ki+a(xe−xs)/ki,ydp/ki+b(ye−ys)/ki).

Accordingly, the display area that has moved in the thumbnail imagebefore enlargement is a rectangular area A67C in the thumbnail imageillustrated in the left part of FIG. 67C. The lower right coordinatesR67C of the rectangular area A67C are given by the following expression:(xdp/ki+a(xe−xs)+wd/2ki,ydp/ki+b(ye−ys)/ki+hd/2ki).

Referring back to FIG. 66, in S7000, the image enlargement unit 1132generates an enlarged thumbnail images in the display area, by using thecoordinates of the display area in the thumbnail image beforeenlargement after display area has moved, which is input from thedisplay area determination unit 1131, and the obtained enlargementfactors for the respective thumbnail images. That is, the imageenlargement unit 1132 uses pixel values in the rectangular area A67Cillustrated in the left part of FIG. 67C as targets of enlargement, andenlarges the thumbnail image to generate an enlarged thumbnail imageillustrated in the right part of FIG. 67C.

Next, the flow of a thumbnail image enlargement process performed whenthe user operates the scrollbar 715 after enlarged thumbnail images aredisplayed in the case display area 710 will be described. In thisembodiment, as illustrated in FIG. 10 or FIG. 11, all the thumbnailimages displayed in the case display area 710 have been enlarged.

FIG. 68 is a flowchart illustrating a thumbnail image enlargementprocess performed when the user operates the scrollbar 715 afterenlarged thumbnail images are displayed in the case display area 710.FIG. 69 is a diagram illustrating the basic screen K2 on which enlargedthumbnail images are being displayed in the case display area 710.

In the state illustrated in FIG. 69, the user scrolls the scrollbar 715down. Then, the input control unit 103 detects the amount of operationperformed on the scrollbar 715, and notifies the enlarged imagegeneration unit 112 of the detected amount of operation. Then, theenlarged image generation unit 112 starts the process illustrated inFIG. 68.

In S4600, the enlarged image generation unit 112 obtains the number ofcases Ns to be additionally displayed in the case display area 710 inresponse to the operation performed on the scrollbar 715 by the user.Specifically, the enlarged image generation unit 112 obtains, from thedisplay control unit 104, the predetermined maximum number ND of resultsallowed to be displayed in the case display area 710. In thisembodiment, as illustrated in FIG. 6, the maximum number ND of resultsallowed to be displayed is four rows and five columns, or 20.Accordingly, five additional thumbnail images are to be displayed. Thus,the enlarged image generation unit 112 obtains Ns=5.

In S4600, furthermore, the enlarged image generation unit 112 identifiesthe similar case IDs of the thumbnail images to be additionallydisplayed in the case display area 710. In this case, the enlarged imagegeneration unit 112 refers to the similarities of the similar cases,which are received from the similar case search unit 303 of the casesearch system 300. The display control unit 104 currently displays thethumbnail images of the ND similar cases in order from highestsimilarity to lowest similarity. Thus, the enlarged image generationunit 112 sets the similar cases having the (ND+1)-th highest similarityto the (ND+Ns)-th highest similarity as cases that are target ofenlargement. The enlarged image generation unit 112 identifies thesimilar case IDs of the targets of enlargement.

In S4700, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. Then, the enlarged imagegeneration unit 112 repeatedly performs the processing of S4800 andS4500 until the index i has reached Ns. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S4800and S4500 is executed. If the index i exceeds Ns (NO in S4700), theprocess illustrated in FIG. 68 ends.

In S4800, the enlarged image generation unit 112 calculates anenlargement factor ki for the similar case i to be subjected toenlargement. Enlarged thumbnail images have been displayed in the casedisplay area 710. Thus, the enlarged image generation unit 112 uses theenlargement factor kr for the reference thumbnail image, which isdetermined in S4100 in FIG. 56. Then, similarly to S4400 in FIG. 56, theenlarged image generation unit 112 calculates the enlargement factor kifor the similar case i to be subjected to enlargement. The processing ofS4500 is substantially the same as that of S4500 in FIG. 56, and is notdescribed in detail herein. Through the process illustrated in FIG. 68,a screen illustrated in FIG. 70 is obtained.

FIG. 70 is a diagram illustrating the basic screen K2 on which enlargedthumbnail images have moved from the state illustrated in FIG. 69. Asillustrated in FIG. 70, the thumbnail images of the similar cases beingdisplayed in the case display area 710 have moved upward in response tothe operation of the scrollbar 715.

In a case where the user continues to operate the scrollbar 715, theenlarged image generation unit 112 further executes the processillustrated in FIG. 68.

Through the process described above, even if a large number of similarcases exist, it may be sufficient that the enlarged image generationunit 112 performs an enlargement process on thumbnail images which arenewly displayed in the case display area 710 through the operation ofthe scrollbar 715. This results in a significantly reduced load on asystem.

Next, an enlargement process performed when a distribution of lesionsdisplayed in the distribution list display area 750 illustrated in FIG.21, FIG. 23, and FIG. 25 is selected will be described. FIG. 71 is aflowchart illustrating a process performed when a distribution oflesions displayed in the distribution list display area 750 is selected.

In S2000, when the input control unit 103 detects an operation ofselecting any one distribution check item among the distributions oflesions (or distribution check items) displayed in the distribution listdisplay area 750, the enlarged image generation unit 112 determineswhich of the first distribution information, the second distributioninformation, and the third distribution information the detecteddistribution check item corresponds to. If the detected distributioncheck item corresponds to the first distribution information, theprocess proceeds to S1301. If the detected distribution check itemcorresponds to the second distribution information, the process proceedsto S1302. If the detected distribution check item corresponds to thethird distribution information, the process proceeds to S1303.

The first distribution information is information for selecting athumbnail image in which the region of interest belongs to apredetermined first range indicating that the size of the region ofinterest is wide relative to the lung area among the thumbnail images ofthe similar cases displayed in list form in the case display area 710.By way of example, the first distribution information includes“bilateral”, “multiple”, “diffuse”, and “hematogenous”. Accordingly, thefirst range is a range of values to which the size of the region ofinterest set for the diagnosis of such distributions of lesions belongs.

The second distribution information is information for selecting athumbnail image in which the region of interest belongs to apredetermined second range (lower than first range; the upper limit ofthe second range is less than or equal to the lower limit of the firstrange) indicating that the size of the region of interest is part of thelung area among the thumbnail images of the similar cases displayed inlist form in the case display area 710. By way of example, the seconddistribution information includes “bronchial” and “segmental”.Accordingly, the second range is a range of values to which the size ofthe region of interest set for the diagnosis of such distributions oflesions belongs.

The third distribution information is information for selecting athumbnail image in which the region of interest has a size so as toexist in an edge of the pleura among the thumbnail images of the similarcases displayed in list form in the case display area 710. By way ofexample, the third distribution information includes “subpleural”.

In S1301, the enlarged image generation unit 112 extracts similar cases,which are obtained as a result of the similar case search and the numberof which is less than or equal to the maximum number of (in thisembodiment, 20) thumbnail images that can be displayed in the casedisplay area 710, among the similar cases of the distributions oflesions selected as the first distribution information by the user, inorder of decreasing similarity, and determines the number of extractedsimilar cases as the number of similar cases NZ1 to be subjected toenlargement. Further, the enlarged image generation unit 112 determinesa thumbnail image of an extracted similar case i (where i is an indexidentifying an extracted similar case, and is an integer greater than orequal to 1) as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2100 andS1501 until the index i has reached NZ1. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2100and S1501 is executed. If the index i exceeds NZ1 (NO in S1301), theprocess illustrated in FIG. 71 ends.

In S2100, the enlarged image generation unit 112 calculates a firstenlargement factor for the first distribution information on the similarcase i. The first enlargement factor is, for example, 1.0. This is anexample, and any value other than 1.0 may be used as the firstenlargement factor as long as the entire region of interest set for thediagnosis of a distribution of lesions indicated by the firstdistribution information falls within the display area.

In S1501, a process similar to S4500 in FIG. 56 is performed. As aresult, the display control unit 104 displays in the case display area710 an image obtained by enlarging the thumbnail image of the similarcase i with the first enlargement factor for the similar case i.

In FIG. 22 described above, “bilateral” is selected. In this case,thumbnail images of similar cases exhibiting bilateral lesiondistribution among the similar cases are displayed in the case displayarea 710. In addition, since the enlargement factor is 1.0, thethumbnail images are displayed in the same display style as thethumbnail images displayed in the case display area 710 immediatelyafter similar case search results are obtained. That is, the thumbnailimages are displayed without adjusting the display positions of thethumbnail images so that the center of the region of interest ROI ineach thumbnail image matches the center of a display area 6801 orwithout enlarging the thumbnail images.

In S1302, the enlarged image generation unit 112 extracts similar cases,which are obtained as a result of the similar case search and the numberof which is less than or equal to the maximum number of thumbnail imagesthat can be displayed in the case display area 710, among the similarcases of the distributions of lesions selected as the seconddistribution information by the user, in order of decreasing similarity,and determines the number of extracted similar cases as the number ofsimilar cases NZ2 to be subjected to enlargement. Further, the enlargedimage generation unit 112 determines a thumbnail image of an extractedsimilar case i as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2200 andS1502 until the index i has reached NZ2. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2200and S1502 is executed. If the index i exceeds NZ2 (NO in S1302), theprocess illustrated in FIG. 71 ends.

In S2200, the enlarged image generation unit 112 calculates a secondenlargement factor corresponding to the second distribution informationon the similar case i by using a display area size determined in advancefor each thumbnail image in the case display area 710 and theregion-of-interest information on the similar case i.

If the second distribution information is selected, the enlarged imagegeneration unit 112 enlarges the similar case i so that the size of theregion of interest is equal to approximately one half of the size of thedisplay area.

Accordingly, for example, the enlarged image generation unit 112computes a second enlargement factor ki for the similar case i inaccordance with the following equation:ki=1/2(Sd/Si),where Sd denotes the area of the display area and Si denotes the area ofthe region of interest in the thumbnail image of the similar case i tobe subjected to enlargement.

In S1502, a process similar to S4500 in FIG. 56 is performed. As aresult, the enlarged image generation unit 112 enlarges the thumbnailimage of the similar case i with the second enlargement factor ki. Thedisplay control unit 104 displays the thumbnail image enlarged by theenlarged image generation unit 112 in the case display area 710 so thatthe center of the region of interest in the thumbnail image matches thecenter of the display area.

In FIG. 24 described above, “bronchial” is selected. In this case,thumbnail images of similar cases exhibiting bronchial lesiondistribution among the similar cases are displayed in the case displayarea 710. In addition, all the thumbnail images in the case display area710 have been enlarged with the second enlargement factor so that thecenter of the region of interest ROI in each thumbnail image matches thecenter of a display area 6901.

In S1303, the enlarged image generation unit 112 extracts similar cases,which are obtained as a result of the similar case search and the numberof which is less than or equal to the maximum number of thumbnail imagesthat can be displayed in the case display area 710, among the similarcases of the distributions of lesions selected as the third distributioninformation by the user, in order of decreasing similarity, anddetermines the number of extracted similar cases as the number ofsimilar cases NZ3 to be subjected to enlargement. Further, the enlargedimage generation unit 112 determines a thumbnail image of an extractedsimilar case i as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2300 andS1503 until the index i has reached NZ3. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2300and S1503 is executed. If the index i exceeds NZ3 (NO in S1303), theprocess illustrated in FIG. 71 ends.

In S2300, the enlarged image generation unit 112 calculates a thirdenlargement factor for the third distribution information on the similarcase i by using a display area size determined in advance for eachthumbnail image in the case display area 710, the region-of-interestinformation on the similar case i, and pleural area information 4900.

FIG. 72 is a diagram illustrating the data configuration of similar casedata 4000 that additionally includes the pleural area information 4900.If the similar case data 4000 does not have registered therein thepleural area information 4900, the pleural area information 4900 is notobtained. In this case, it may be sufficient that the enlarged imagegeneration unit 112 sets the third enlargement factor to 1.0, which isequal to the first enlargement factor. The pleural area information 4900is information indicating the pleural area in a similar case.

In S1503, a process similar to S4500 in FIG. 56 is performed. As aresult, the enlarged image generation unit 112 enlarges the thumbnailimage of the similar case i with the third enlargement factor ki. Thedisplay control unit 104 displays the thumbnail image enlarged by theenlarged image generation unit 112 in the case display area 710 so thatthe center of the region of interest in the thumbnail image matches thecenter of the display area.

FIG. 73 is a diagram depicting a pleural area 7101. As illustrated inFIG. 73, the pleural area 7101 includes the pleura and is a rectangulararea that is centered on the center of the region of interest ROI andthat has a slightly larger size than the region of interest ROI. Thepleural area information 4900 includes four values, namely, thecoordinates (xpl, ypt) of the upper left corner of the pleural area 7101and the coordinates (xpr, ypb) of the lower right corner of the pleuralarea 7101. If the third distribution information is selected, thepleural area is enlarged and displayed. Thus, the enlarged imagegeneration unit 112 computes the third enlargement factor ki inaccordance with the following equation:ki=Sd/Sp,where Sd denotes the area of a display area 7102 and Sp denotes the areaof the pleural area 7101.

The user may input the pleural area information 4900 together withregion-of-interest information when creating the similar case data 4000.Alternatively, the pleural area information 4900 may be automaticallycreated by automatically extracting the lung area from a slice image anddetermining the pleural position using an image processing device.

In FIG. 26 described above, “subpleural” is selected. In this case, onlythumbnail images of similar cases exhibiting subpleural lesiondistribution among the similar cases are displayed in the case displayarea 710. In addition, all the thumbnail images in the case display area710 have been enlarged with the third enlargement factor so that thecenter of the region of interest ROI in each thumbnail image matches thecenter of a display area 7001.

Through the process described above, thumbnail images are displayed inthe case display area 710 with an enlargement factor that reflects thecontent of the diagnosis regarding a distribution of lesions. Inaddition, the thumbnail images are displayed in the case display area710 with uniformity in size across the regions of interest in theindividual thumbnail images. This may prevent the occurrence ofoversight caused by the way in which the region of interest in somesimilar medical images has been enlarged but is small, and may improvediagnosis accuracy. In addition, not all the similar cases obtained as aresult of the similar case search but similar cases displayed in thecase display area 710 are subjected to an enlargement process, resultingin a significantly reduced load on a system.

Second Embodiment

In the first embodiment, an enlargement factor for a thumbnail image ofa similar case is controlled in accordance with the amount of operationperformed on the operation unit 102 by the user. In a second embodiment,the enlargement factor is controlled on the basis of a user operation onan enlargement factor change button on a basic screen.

FIG. 74 is a diagram illustrating a basic screen K2 on which thumbnailimages of similar cases retrieved as a result of the similar case searchare being displayed in the case display area 710 according to a secondembodiment. The following description will focus mainly on the portionsdifferent from those in the first embodiment described above.

In the second embodiment, the basic screen K2 includes an enlargementfactor change button 716 (an example of an instruction button). Asillustrated in FIG. 74, the basic screen K2 includes, as the enlargementfactor change button 716, a first instruction button 717, a secondinstruction button 718, and a third instruction button 719.

In the second embodiment, when the user selects any one of the firstinstruction button 717, the second instruction button 718, and the thirdinstruction button 719 included in the enlargement factor change button716, the input control unit 103 detects the selection of the instructionbutton. Then, the input control unit 103 notifies the enlarged imagegeneration unit 112 of information on the button selected by the user.The enlarged image generation unit 112 changes the enlargement factorfor all the thumbnail images displayed in the case display area 710 inaccordance with the notified information on the selected button.

If the first instruction button 717 is selected by the user, theenlarged image generation unit 112 calculates the enlargement factor tobe 1.0. The first instruction button 717 is selected on the initialbasic screen K2 after the similar case search is made. Accordingly, theenlargement factor for the thumbnail images on the basic screen K2illustrated in FIG. 74 is 1.0. In FIG. 74, furthermore, the displaycontrol unit 104 changes the color of the first instruction button 717.

FIG. 75 is a diagram illustrating the basic screen K2, which is obtainedwhen the second instruction button 718 is selected by the user. FIG. 76is a diagram illustrating the basic screen K2, which is obtained whenthe third instruction button 719 is selected by the user.

In FIG. 75, the display control unit 104 changes the color of the secondinstruction button 718. In FIG. 76, the display control unit 104 changesthe color of the third instruction button 719.

If the second instruction button 718 is selected by the user on thebasic screen K2 illustrated in FIG. 74 or FIG. 76, as illustrated inFIG. 75, the enlarged image generation unit 112 calculates theenlargement factors for the respective thumbnail images so that theregion of interest ROI is enlarged in such a manner that the size of theregion of interest ROI is equal to approximately one half of the size ofa display area 5801.

If the third instruction button 719 is selected by the user on the basicscreen K2 illustrated in FIG. 74 or FIG. 75, as illustrated in FIG. 76,the enlarged image generation unit 112 calculates the enlargementfactors for the respective thumbnail images so that the region ofinterest ROI is enlarged in such a manner that the size of the region ofinterest ROI is approximately equal to the size of a display area 5901.

In FIG. 75 and FIG. 76, thumbnail images of similar cases, the number ofwhich is equal to M (in FIG. 75 and FIG. 76, M=20), are displayed in thecase display area 710 in which the maximum number of results allowed tobe displayed is equal to ND (in this embodiment, ND=20), and M (in FIG.75 and FIG. 76, M=20) thumbnail images are enlarged. In the mannerdescribed above, in the second embodiment, all the thumbnail imagesdisplayed in the case display area 710 are enlarged. For example, asillustrated in FIG. 18, if M=14, all the 14 thumbnail images areenlarged.

FIG. 77 is a diagram schematically illustrating a drag operation 7701performed by a user while the basic screen K2 (FIG. 75) on which thesecond instruction button 718 is selected by the user is beingdisplayed. FIG. 78 is a diagram schematically illustrating a dragoperation 7701 performed by a user while the basic screen K2 (FIG. 76)on which the third instruction button 719 is selected by the user isbeing displayed.

As illustrated in FIG. 77 and FIG. 78, the user selects one of theenlarged thumbnail images in the case display area 710. In FIG. 77 andFIG. 78, a thumbnail image of a display area 7702 in the third row andthe third column is selected. When the user performs the drag operation7701 in this state, the input control unit 103 detects the amount ofmovement of the mouse, and notifies the enlarged image generation unit112 of the detected amount of movement. Then, the enlarged imagegeneration unit 112 determines an amount of movement of a display areain a thumbnail image by using the detected amount of movement of themouse, and generates a thumbnail image in which the display area hasmoved the determined amount. The display control unit 104 displays, inthe case display area 710, thumbnail images that have been caused tomove by the enlarged image generation unit 112.

Specifically, as illustrated in FIG. 77 and FIG. 78, the user performsthe drag operation 7701 to drag the mouse to the left, causing thedisplay areas of the 20 thumbnail images displayed in the case displayarea 710 in enlarged form to move so that the portion to the right ofthe corresponding region of interest CROI in each of the 20 thumbnailimages appears. This eliminates the need for the user to individuallyperform a movement operation on the 20 similar cases displayed in thecase display area 710 in enlarged form, and may significantly reduce thenumber of operations.

Next, an enlargement process performed when the user selects theenlargement factor change button 716 will be described.

FIG. 79 is a flowchart illustrating an enlargement process performedwhen a user selects the enlargement factor change button 716.

In S2800, the enlarged image generation unit 112 determines a target tobe subjected to an enlargement process among a large number of similarcases obtained as a result of the similar case search.

In the second embodiment, unlike the first embodiment (84100 in FIG.56), instead of the user selecting a thumbnail image of a referencesimilar case, the user selects the enlargement factor change button 716.Thus, the enlarged image generation unit 112 regards all the similarcases displayed in the case display area 710 when the user selects theenlargement factor change button 716, as targets to be subjected to anenlargement process. Accordingly, the enlarged image generation unit 112obtains, from the similar case data 4000 (FIG. 33), the similar case IDsof all the thumbnail images displayed in the case display area 710.

In S2400, the enlarged image generation unit 112 determines the type ofthe button selected by the user on the basis of the button informationof which the enlarged image generation unit 112 is notified by the inputcontrol unit 103. If the button selected by the user is the firstinstruction button 717, the process proceeds to S2451. If the selectedbutton is the second instruction button 718, the process proceeds toS2452. If the selected button is the third instruction button 719, theprocess proceeds to S2543.

In S2451, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2500 andS4501 until the index i has reached ND. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2500and S4501 is executed. If the index i exceeds ND (NO in S2451), theprocess illustrated in FIG. 79 ends.

In S2500, the first instruction button 717 has been selected by theuser. Thus, in S2500, the enlarged image generation unit 112 calculatesthe enlargement factor to be 1.0.

In S4501, a process similarly to S4500 in FIG. 56 is performed. As aresult, since the enlargement factor is 1.0, as illustrated in FIG. 74,the display control unit 104 displays the thumbnail image in the samedisplay style as the thumbnail image displayed in the case display area710 immediately after similar case search results are obtained.

In S2452, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2600 andS4502 until the index i has reached ND. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2600and S4502 is executed. If the index i exceeds ND (NO in S2452), theprocess illustrated in FIG. 79 ends.

In S2600, the second instruction button 718 has been selected by theuser. Thus, in S2600, as described above, the enlarged image generationunit 112 calculates an enlargement factor for the enlargement-intendedthumbnail image i so that the size of the region of interest is equal toapproximately one half of the size of the display area. The enlargedimage generation unit 112 calculates the enlargement factor on the basisof the size of the display area and the region-of-interest information4300 in the similar case data 4000 (FIG. 33) of the enlargement-intendedthumbnail image i. The enlarged image generation unit 112 computes anenlargement factor ki in accordance with an equation below. Given thatthe area of a display area 5701 (FIG. 74) is represented by Sd and thearea of the region of interest ROI (FIG. 74) in the enlargement-intendedthumbnail image i is represented by Si, the enlargement factor ki forthe thumbnail image of the similar case i to be subjected to enlargementcan be calculated in accordance with the following equation:ki=1/2(Sd/Si).

In S4502, a process similar to S4500 in FIG. 56 is performed. As aresult, the enlarged image generation unit 112 enlarges the thumbnailimage of the similar case i so that the center of the region of interestin the thumbnail image matches the center of the display area. Thedisplay control unit 104 displays the enlarged thumbnail image generatedby the enlarged image generation unit 112 in the case display area 710.

In the second embodiment, when the second instruction button 718 isselected, the enlarged image generation unit 112 calculates anenlargement factor so that the ratio of the size of the region ofinterest to the size of the display area is equal to approximately 1/2.In the present disclosure, however, the ratio is not limited to 1/2. Theratio may be any other value such as 1/3 or 2/3.

In S2453, the enlarged image generation unit 112 determines a thumbnailimage of a similar case i (where i is an index identifying a targetsimilar case to be processed, and is an integer greater than or equalto 1) as a thumbnail image to be processed. The enlarged imagegeneration unit 112 repeatedly performs the processing of S2700 andS4503 until the index i has reached ND. The enlarged image generationunit 112 increments the index i by 1 each time the processing of S2700and S4503 is executed. If the index i exceeds ND (NO in S2453), theprocess illustrated in FIG. 79 ends.

In S2700, the third instruction button 719 has been selected by theuser. Thus, in S2700, as described above, the enlarged image generationunit 112 calculates an enlargement factor for the enlargement-intendedthumbnail image i so that the size of the region of interest isapproximately equal to the size of the display area. The enlarged imagegeneration unit 112 calculates the enlargement factor on the basis ofthe size of the display area and the region-of-interest information 4300in the similar case data 4000 (FIG. 33) of the similar case i to besubjected to enlargement. The enlarged image generation unit 112computes an enlargement factor ki in accordance with an equation below.Given that the area of a display area 5701 (FIG. 74) is represented bySd and the area of the region of interest ROI (FIG. 74) in the thumbnailimage of the similar case i to be subjected to enlargement isrepresented by Si, the enlargement factor ki for the thumbnail image ofthe similar case i to be subjected to enlargement can be calculated inaccordance with the following equation:ki=Sd/Si.

In S4503, a process similar to S4500 in FIG. 56 is performed. As aresult, the enlarged image generation unit 112 enlarges the thumbnailimage of the similar case i so that the center of the region of interestin the thumbnail image matches the center of the display area. Thedisplay control unit 104 displays the enlarged thumbnail image generatedby the enlarged image generation unit 112 in the case display area 710.

In the second embodiment, when the third instruction button 719 isselected, the enlarged image generation unit 112 calculates anenlargement factor so that the ratio of the size of the region ofinterest to the size of the display area is equal to approximately 1.0.In the present disclosure, however, the ratio is not limited to 1.0. Theratio may be any other value such as 1.1 or 0.9.

Through the process described above, the sizes of the regions ofinterest ROI in the individual display areas within the case displayarea 710 can be made uniform. This may prevent the occurrence ofoversight caused by the way in which the region of interest in somesimilar medical images has been enlarged but is small, and may improvediagnosis accuracy. In this case, not all the similar cases obtained asa result of the similar case search but similar cases displayed in thecase display area 710 are subjected to an enlargement process. Thisresults in a significantly reduced load on a system.

Next, a process performed during a period in which, after thumbnailimages obtained as a result of the similar case search are enlarged anddisplayed on the information terminal 100, a display area of a thumbnailimage is changed in response to a user operation will be described. Inthe following, first, the details of the processing blocks of theenlarged image generation unit 112 will be described, and then the flowof the display area changing process will be described.

FIG. 80 is a block diagram illustrating the detailed configuration ofthe enlarged image generation unit 112 according to the secondembodiment. The enlarged image generation unit 112 includes an inputdetermination unit 1141, a target determination unit 1142, anenlargement factor determination unit 1143, an image enlargement unit1125, a first display area determination unit 1126, anamount-of-movement determination unit 1127, a display image generationunit 1129, and a second display area determination unit 1128. Theenlarged image generation unit 112 performs an enlargement factorchanging process and a display area changing process. In the secondembodiment, substantially the same processing blocks as those in thefirst embodiment are assigned the same numerals, and are not describedin detail herein.

The input determination unit 1141 determines the content of theoperation performed on the operation unit 102 by a user, of which theenlarged image generation unit 112 is notified by the input control unit103. If the determined content of the operation indicates an enlargementfactor changing operation (in the second embodiment, the selection of abutton), the input determination unit 1141 outputs the type of theselected button (that is, the first instruction button 717, the secondinstruction button 718, or the third instruction button 719) to theenlargement factor determination unit 1143. The input determination unit1141 outputs operation content information (information indicating achange of the enlargement factor, for example, the value “1” preset as avalue corresponding to information indicating a change of theenlargement factor) to the target determination unit 1142.

If the determined content of the operation indicates a display areachanging operation (e.g., mouse dragging), the input determination unit1141 outputs the amount of operation (e.g., the start position and endposition of mouse dragging) to the amount-of-movement determination unit1127. The input determination unit 1141 further outputs operationcontent information (information indicating a change of a display area,for example, the value “2” preset as a value corresponding toinformation indicating a change of a display area) to the targetdetermination unit 1142.

If the determined content of the operation indicates the selection of adistribution of lesions (checking the checkbox for the distribution listdisplay area 750), the input determination unit 1141 outputsdistribution information to which the selected distribution of lesionsbelongs, that is, the first distribution information, the seconddistribution information, or the third distribution information, to theenlargement factor determination unit 1143. The input determination unit1141 outputs operation content information (information indicating achange of the enlargement factor in response to the selection of adistribution of lesions, for example, the value “3” preset as a valuecorresponding to information indicating a change of the enlargementfactor in response to the selection of a distribution of lesions) to thetarget determination unit 1142.

The target determination unit 1142 determines a similar case to besubjected to a thumbnail image enlargement process or a display areachanging process, on the basis of the operation content informationinput from the input determination unit 1141.

In the second embodiment, the enlargement factor changing operation isan operation on the first instruction button 717, the second instructionbutton 718, or the third instruction button 719. In a case where theoperation content information is information indicating a change of theenlargement factor, the target determination unit 1142 determines allthe (in the examples illustrated in FIG. 74 to FIG. 76, 20) similarcases displayed on the display 101 as targets to be subjected to anenlargement process. The target determination unit 1142 outputs thenumber of similar cases and the similar case IDs 4100 of the similarcases to the enlargement factor determination unit 1143.

If the operation content information is information indicating a changeof a display area, the target determination unit 1142 uses the similarcases to be subjected to enlargement, which are determined in theenlargement factor changing process, directly as targets to be subjectedto the display area changing process.

If the operation content information is information indicating a changeof the enlargement factor in response to the selection of a distributionof lesions, the target determination unit 1142 outputs the similar caseIDs 4100 obtained as a result of refinement in accordance with aselected distribution of lesions, and the number of similar case IDs4100 to the enlargement factor determination unit 1143.

The enlargement factor determination unit 1143 determines an enlargementfactor for the similar cases that are targets of enlargement, which aredetermined by the target determination unit 1142. If informationindicating the selected distribution of lesions is input from the inputdetermination unit 1141 as operation content information, theenlargement factor determination unit 1143 calculates a predeterminedenlargement factor corresponding to the selected distribution oflesions. The enlargement factor determination unit 1143 outputs thedetermined enlargement factor, and the similar case IDs 4100 of thetargets of enlargement and the number of similar case IDs, which areinput from the target determination unit 1142, to the image enlargementunit 1125. Predetermined enlargement factors corresponding to therespective distributions of lesions are as described above withreference to FIG. 21 to FIG. 26.

If information indicating a change of the enlargement factor is inputfrom the input determination unit 1141 as operation content information,the enlargement factor determination unit 1143 extracts theregion-of-interest information 4300 corresponding to the similar caseIDs 4100 (FIG. 33) of the targets of enlargement, which are input fromthe target determination unit 1142. The enlargement factor determinationunit 1143 calculates enlargement factors for the respective similarcases by using the extracted region-of-interest information 4300 and thetype of the button (that is, the first instruction button 717, thesecond instruction button 718, or the third instruction button 719)input from the input determination unit 1141 through the proceduredescribed above with reference to FIG. 79. The enlargement factordetermination unit 1143 outputs the calculated enlargement factors, thesimilar case IDs 4100 of the targets of enlargement, and the number ofsimilar case IDs to the image enlargement unit 1125.

Also in the second embodiment, similarly to the first embodiment, when adistribution of lesions that belongs to the first distributioninformation is selected, display areas are not changed. In the secondembodiment, furthermore, in a case where the enlargement factor ischanged in response to the operation on the first instruction button717, as illustrated in FIG. 74, entire thumbnail images are displayedwith an enlargement factor of 1.0. Thus, also when the enlargementfactor is changed in response to the operation on the first instructionbutton 717, the display areas are not changed.

In the second embodiment, accordingly, in a case where a distribution oflesions that belongs to the first distribution information is selectedand the enlargement factor is changed in response to the operation onthe first instruction button 717, the input determination unit 1141 maynot necessarily output the amount of operation to the amount-of-movementdetermination unit 1127 even if the determined content of the operationindicates a display area changing operation. Alternatively, the targetdetermination unit 1142 may determine that none of the similar cases isset as a target to be subjected to a display area changing process.

Next, the flow of a process for changing a display area in an enlargedthumbnail image will be described.

FIG. 81 is a flowchart illustrating a process for changing the displayarea for an enlarged thumbnail image. In FIG. 81, substantially the samesteps as those illustrated in FIG. 64 are assigned the same numerals,and are not described in detail herein.

In S7100, the target determination unit 1142 obtains a similar case tomove on which a display area changing process is to be performed. In thesecond embodiment, similarly to the first embodiment, in S7100, thetarget determination unit 1142 uses, as a similar case to move, asimilar case for which the enlargement factor has been changed in theenlargement factor changing process. This step may reduce the processingload on the information terminal 100, compared to the case where displayareas for all the NC similar cases received from the similar case searchunit 303 move.

As described above, in the second embodiment, in a case where adistribution of lesions that belongs to the first distributioninformation is selected and the enlargement factor is changed inresponse to the operation on the first instruction button 717, displayareas are not changed.

Accordingly, in a case where a distribution of lesions that belongs tothe first distribution information has been selected and the enlargementfactor has been changed in response to the operation on the firstinstruction button 717, then in S7100, the target determination unit1142 may determine that none of the similar cases is set as a target tobe subjected to a display area changing process, and the process mayend. Alternatively, in S7100, the target determination unit 1142 may setthe index i to a value exceeding NZ, and may obtain a negativedetermination in S6300.

The configuration of the enlarged image generation unit 112 thatperforms a display area changing process is not limited to thatillustrated in FIG. 80. Next, a modification of the display areachanging process will be described.

FIG. 82 is a block diagram illustrating a detailed configuration of theenlarged image generation unit 112, which is different from thatillustrated in FIG. 80. The enlarged image generation unit 112 includesthe input determination unit 1141, the target determination unit 1142,the enlargement factor determination unit 1143, an amount-of-movementdetermination unit 1130, a display area determination unit 1131, and animage enlargement unit 1132. In FIG. 82, substantially the same blocksas those in FIG. 65 and FIG. 80 are assigned the same numerals.

The amount-of-movement determination unit 1130 obtains the determinedenlargement factors for the respective thumbnail images from theenlargement factor determination unit 1143. The amount-of-movementdetermination unit 1130 obtains the amount of operation from the inputdetermination unit 1121. The amount-of-movement determination unit 1130calculates the amount of movement in the thumbnail image beforeenlargement, by using the enlargement factors for the respectivethumbnail images and the amount of operation. The amount-of-movementdetermination unit 1130 outputs the calculated amount of movement andthe enlargement factors for the respective thumbnail images to thedisplay area determination unit 1131.

Similarly to the first display area determination unit 1126, the displayarea determination unit 1131 determines a display area in the enlargedthumbnail image of the similar case that is a target of enlargement.That is, the display area determination unit 1131 obtains the similarcase ID 4100 (FIG. 33) of the target of enlargement from the enlargementfactor determination unit 1143. The display area determination unit 1131extracts the region-of-interest information 4300 corresponding to theobtains similar case ID 4100 (FIG. 33) of the target of enlargement. Thedisplay area determination unit 1131 calculates the coordinates of thedisplay area in the enlarged thumbnail image by using the enlargementfactor input from the enlargement factor determination unit 1143 and theextracted region-of-interest information 4300 through the proceduredescribed above with reference to S4520 and S4530 in FIG. 59.

The display area determination unit 1131 obtains the enlargement factorsfor the respective thumbnail images from the enlargement factordetermination unit 1143. The display area determination unit 1131obtains the amount of movement in the thumbnail image before enlargementfrom the amount-of-movement determination unit 1130. The display areadetermination unit 1131 calculates the coordinates of the display areain the thumbnail image before enlargement before the display area hasmoved, by using the calculated coordinates of the display area in theenlarged thumbnail image and the obtains enlargement factors.

The display area determination unit 1131 adds the obtained amount ofmovement in the thumbnail image before enlargement to the calculatedcoordinates of the display area in the thumbnail image beforeenlargement before the display area has moved to calculate thecoordinates of the display area in the thumbnail image beforeenlargement after display area has moved. The display area determinationunit 1131 outputs the calculated coordinates of the display area in thethumbnail image before enlargement after display area has moved to theimage enlargement unit 1132.

The image enlargement unit 1132 obtains the enlargement factors for therespective thumbnail images from the enlargement factor determinationunit 1143. The image enlargement unit 1132 enlarges thumbnail images inthe display area, by using the coordinates of the display area in thethumbnail image before enlargement after display area has moved, whichare input from the display area determination unit 1131, and theobtained enlargement factors for the respective thumbnail images. Theimage enlargement unit 1132 outputs the generated enlarged thumbnailimages to the display control unit 104.

A description will be given here of the meaning of the modificationsillustrated in FIG. 65 and FIG. 82. As described above with reference toFIG. 60, the enlarged thumbnail image illustrated in the right part ofFIG. 60 is generated from the original thumbnail image illustrated inthe left part of FIG. 60. For example, in a case where the entireenlarged thumbnail image illustrated in the right part of FIG. 60 isstored, as described above with reference to FIG. 63, it may besufficient that the display area is changed (or caused to move) over theenlarged thumbnail image in accordance with the amount of operationperformed by the user.

In some cases, only a portion of the enlarged thumbnail imageillustrated in the right part of FIG. 60, which corresponds to thedisplay area illustrated in FIG. 67A, may be stored. In particular, inthe second embodiment, the enlargement factor changing process isperformed in response to the selection of any distribution of lesionsamong the “diffuse” 751 to the “hematogenous” 757 (e.g., FIG. 20) or inresponse to the operation on any of the first to third instructionbuttons 717 to 719 (e.g., FIG. 74). That is, in the second embodiment,an enlargement factor is determined in advance independently of theamount of operation performed by the user.

In the second embodiment, accordingly, it is conceivable that athumbnail image produced by enlarging the original thumbnail image witha predetermined enlargement factor is created in advance and only aportion of the thumbnail image, which corresponds to the display area(FIG. 67A) to be displayed in the case display area 710, is stored. Inthis case, it will be difficult to use the technique illustrated in FIG.63 in which a display area is caused to directly move over an enlargedthumbnail image. In this case, it may be effective that the display areabe changed (or be caused to move) with the configuration according tothe modifications illustrated in FIG. 65 and FIG. 82 through theprocedure described above with reference to FIGS. 67A to 67C.

In the foregoing, an example has been provided in which the process forchanging an enlargement factor for a thumbnail image is executed by theinformation terminal 100. In the case of a process for changing theenlargement factor by using the enlargement factor change button 716according to the second embodiment, the enlargement factor changingprocess may be executed by the case search system 300. In this case, thecase search system 300 may generate in advance a thumbnail image with achanged enlargement factor. When an enlargement factor change button isoperated, the thumbnail image may be transmitted from the case searchsystem 300 to the information terminal 100.

FIG. 83 is a sequence diagram illustrating a process performed during aperiod in which, after the case search system 300 transmits similar casesearch results to the information terminal 100, the enlargement factorchange button 716 is selected on the information terminal 100 andenlarged thumbnail images are displayed on the display 101 b of theinformation terminal 100. FIG. 84 is a flowchart illustratingpre-processing executed in the case search system 300 and the processillustrated in FIG. 83. In FIG. 84, substantially the same processingsteps as those illustrated in FIG. 83 are assigned the same numerals.The process will be described in detail with reference to FIG. 83 andFIG. 84.

First, pre-processing executed in the case search system 300 will bedescribed. In S3100 in FIG. 84, the case search system 300 determinesthe enlargement factors for the respective thumbnail images for each ofthe first instruction button 717, the second instruction button 718, andthe third instruction button 719 of the enlargement factor change button716. The procedure for determining the enlargement factors may be theprocedure described above with reference to S2500, S2600, and S2700 inFIG. 79.

In S3110, the case search system 300 generates enlarged thumbnail imagedata for each of the first instruction button 717, the secondinstruction button 718, and the third instruction button 719 inaccordance with the enlargement factor determined in S3100 and thethumbnail image data 4500 of the similar case data 4000 (FIG. 33). Asillustrated in FIG. 85, the case search system 300 stores the generatedenlarged thumbnail image data in the similar case data accumulation unit301 as enlarged thumbnail data 5000, separately from the similar casedata 4000 (FIG. 33).

FIG. 85 is a diagram illustrating the data configuration of the enlargedthumbnail data 5000. The enlarged thumbnail data 5000 is data forstoring enlarged thumbnail image data in the similar case dataaccumulation unit 301. As illustrated in FIG. 85, the enlarged thumbnaildata 5000 includes, is association with similar case ID 5100, enlargedthumbnail image data 5200 corresponding to the first instruction button717, enlarged thumbnail image data 5300 corresponding to the secondinstruction button 718, and enlarged thumbnail image data 5400corresponding to the third instruction button 719.

Next, a process performed when the user selects an enlargement factorchange button on the information terminal 100 will be described withreference to FIG. 83 and FIG. 84.

In S3010, the input control unit 103 detects the type of the instructionbutton selected by the user within the enlargement factor change button716. That is, the input control unit 103 detects which of the firstinstruction button 717, the second instruction button 718, and the thirdinstruction button 719 has been selected by the user.

In S3020, the display control unit 104 obtains, from the similar casedata 4000 (FIG. 33), the similar case IDs of ND (in this embodiment,ND=20) similar cases that is being displayed in the case display area710 when the enlargement factor change button 716 is selected by theuser. Further, the display control unit 104 determines the obtainedsimilar case IDs as similar cases to be subjected to enlargement.

In S3030, the communication control unit 110 transmits the type of theenlargement factor change button 716, which is detected by the inputcontrol unit 103 in S3010, and the similar case IDs of the targets ofenlargement (the number of which is equal to ND), which are obtained bythe display control unit 104 in S3020, to the case search system 300.

In S3040, the communication control unit 304 of the case search system300 receives the type of the enlargement factor change button 716 andthe similar case IDs of the targets of enlargement (the number of whichis equal to ND), which are transmitted from the information terminal 100in S3030.

In S3050, the case search system 300 designates image data to be usedfor display among the enlarged thumbnail image data 5200, 5300, and 5400in the enlarged thumbnail data 5000, by using the received similar caseIDs and the received type of the enlargement factor change button 716.The communication control unit 304 of the case search system 300transmits the designated enlarged thumbnail image data to theinformation terminal 100.

In S3060, the communication control unit 110 of the information terminal100 receives the enlarged thumbnail image data transmitted from the casesearch system 300.

In S3070, the display control unit 104 of the information terminal 100displays enlarged thumbnail images of the similar cases in the casedisplay area 710 of the display 101 b of the information terminal 100,on the basis of the enlarged thumbnail image data received by thecommunication control unit 110 in S3060.

Supplementary Description of First Embodiment

Next, the process performed by the information terminal 100, the medicalinformation management system 200, and the case search system 300 whenthe focus is on the sequence diagrams illustrated in FIG. 35 and FIG. 39at the application level will be described.

FIG. 86 is a sequence diagram focusing on the sequence diagramsillustrated in FIG. 35 and FIG. 39 at the application level. In FIG. 86,substantially the same processing steps as those in FIG. 35 and FIG. 39are assigned the same numerals.

In FIG. 86 and FIG. 87, part “A” illustrates the process of the medicalinformation management application implemented by the informationterminal 100, and part “B” illustrates the process of the similar casesearch application implemented by the information terminal 100. In thefollowing, the medical information management application is representedby the “app A”, and the similar case search application is representedby the “app B”.

First, the app A accepts a request for displaying a test list for imageinterpretation from the user, and transmits the request to the medicalinformation management system 200 (S510). Upon receipt of the request,the medical information management system 200 lists tests in which imageinterpretation is yet to be performed after the completion of an imagingtest to generate a test list in which image interpretation is to beperformed, and transmits the test list to the app A.

Upon receipt of the test list, the app A displays the test list asillustrated in FIG. 36 on the display 101. When the user selects a testfrom the test list (S530), the app A transmits a request for displayingthe selected test to the medical information management system 200(S540).

Upon receipt of the request for displaying the test, the medicalinformation management system 200 transmits all the slice images in allthe series included in the test ID specified in the request to the app A(S550).

Then, the app A displays a series list as illustrated in FIG. 37 inwhich pieces of information concerning all the series included in thespecified test ID are displayed in list form (S560).

Then, when a series to be interpreted is selected by the user from theseries list, the app A displays the slice image corresponding to theinitial slice position in the selected series in the medical imageviewer 610 (S570). In this case, the user inputs a slice-basedforwarding operation to display the desired slice image in the medicalimage viewer 610.

Then, the app A accepts an operation of setting a region of interest inthe slice image displayed in the medical image viewer 610 from the user(S580).

Then, the app A generates region-of-interest information indicating theregion of interest set by the user, and transmits the region-of-interestinformation together with the slice image in which the region ofinterest has been set (i.e., the slice image of the case to bediagnosed) to the app B (S590, S600).

Upon receipt of the slice image of the case to be diagnosed and theregion-of-interest information, the app B transmits the slice image andthe region-of-interest information to the case search system 300 (S601,S602).

Upon receipt of the slice image and the region-of-interest information,as in FIG. 39, the case search system 300 executes the processing ofS610 to S640.

Then, the app B generates an initial basic screen by using the similarcase data transmitted in S640 and the display box management information4410 (S670). Then, the app B executes the processing of S670, thedetails of which are illustrated in FIG. 44.

FIG. 87 is a sequence diagram focusing on the sequence diagramsillustrated in FIG. 54 and FIG. 55 at the application level. In FIG. 87,substantially the same processing steps as those in FIG. 54 and FIG. 55are assigned the same numerals.

The difference from FIG. 86 is that S603 and S604 are provided. In FIG.87, image features are extracted by the information terminal 100. Tothis end, the app B extracts an image feature from a region of interestset on a slice image of a case to be diagnosed (S603), and transmits theextracted image feature to the case search system 300 (S604).

Aspects of the present disclosure are applicable to a similar casesearch device that presents similar cases to be used as reference fordiagnosis using medical images to be interpreted, an imageinterpretation training device for trainee radiologists, and the like.

What is claimed is:
 1. A control method for controlling an informationterminal for access to a case search system that searches for a medicalimage with reference to a medical image database having medical imagesregistered therein, the information terminal including a display and acomputer, wherein a target medical image that is a medical image to beinterpreted is displayed on the display, the target medical image beingselected from among candidate medical images to be interpreted, thecontrol method comprising: causing the computer of the informationterminal to detect designation information indicating a region ofinterest included in the target medical image; causing the computer ofthe information terminal to receive from the case search system, inaccordance with the region of interest indicated by the designationinformation, a plurality of similar medical images each having a featurevalue having a predetermined similarity to a feature value of the regionof interest, each of the plurality of similar medical images including acorresponding region of interest which corresponds to the region ofinterest; causing the computer of the information terminal to display adisplay screen on the display, the display screen being a screen onwhich a number of similar medical images that is less than or equal to apredetermined value among the received plurality of similar medicalimages are displayed, the display screen including a number of displayframes that is equal to the predetermined value to display the similarmedical images; causing the computer of the information terminal to, inresponse to detection of an instruction for enlarging the similarmedical images being displayed on the display screen, enlarge anddisplay the corresponding regions of interest included in the similarmedical images while maintaining sizes of the display frames unchangedon the display screen; and causing the computer of the informationterminal to, in response to detection of an instruction for causing aselected similar medical image selected from among the enlarged anddisplayed similar medical images to move within a corresponding displayframe among the display frames, cause an unselected similar medicalimage other than the selected similar medical image to movesynchronously with the movement of the selected similar medical imagewithin a display frame corresponding to the unselected similar medicalimage among the display frames in a movement direction identical with amovement direction in which the selected similar medical image moves,wherein a ratio of a movement distance by which the selected similarmedical image moves to a movement distance by which the unselectedsimilar medical image moves corresponds to a ratio of an area of thecorresponding region of interest included in the selected similarmedical image to an area of the corresponding region of interestincluded in the unselected similar medical image.
 2. The control methodaccording to claim 1, wherein, in a case where the area of thecorresponding region of interest included in the selected similarmedical image is larger than the area of the corresponding region ofinterest included in the unselected similar medical image, the movementdistance by which the unselected similar medical image moves is madeshorter than the movement distance by which the selected similar medicalimage moves.
 3. The control method according to claim 1, wherein thetarget medical image has attached information that does not includedisease information on a name of a disease of a lesion displayed in thetarget medical image, and wherein each of the received plurality ofsimilar medical images has attached information that includes diseaseinformation on a name of a disease of a lesion displayed in the image.4. The control method according to claim 3, wherein the display screenincludes a first display area in which the target medical image isdisplayed, and a second display area that includes the display frames,the number of which is equal to the predetermined value.
 5. The controlmethod according to claim 3, wherein the similar medical images, thenumber of which is less than or equal to the predetermined value, amongthe received plurality of similar medical images are displayed in thedisplay frames in order of decreasing similarity to the target medicalimage.
 6. The control method according to claim 1, further comprising:causing the computer of the information terminal to transmit informationindicating a feature value of the region of interest to the case searchsystem; and causing the computer of the information terminal to receivefrom the case search system a similar medical image having a featurevalue having the predetermined similarity to the feature value of theregion of interest.
 7. The control method according to claim 1, furthercomprising: causing the computer of the information terminal to transmitthe target medical image and the designation information indicating theregion of interest to the case search system; and causing the computerof the information terminal to receive from the case search system asimilar medical image having a feature value having the predeterminedsimilarity to a feature value of the region of interest, which isobtained from the target medical image and the designation information.8. The control method according to claim 1, wherein the target medicalimage is a medical image of a lung, wherein each of the similar medicalimages is a medical image of a lung, wherein the display screen includesfirst distribution information for selection of a similar medical imagein which the corresponding region of interest belongs to a predeterminedfirst range indicating that a size of the corresponding region ofinterest is wide relative to the lung area, second distributioninformation for selection of a similar medical image in which thecorresponding region of interest belongs to a predetermined second rangelower than first range, the second range indicating that a size of thecorresponding region of interest is a portion of a lung area, and thirddistribution information for selection of a similar medical image inwhich the corresponding region of interest includes a pleura, andwherein the computer of the information terminal is caused to, inresponse to detection that distribution information has been selectedamong the first distribution information, the second distributioninformation, and the third distribution information, select a similarmedical image corresponding to the selected distribution information andto display the selected similar medical image on the display screen. 9.The control method according to claim 8, wherein the computer of theinformation terminal is caused to in response to detection that thefirst distribution information has been selected, display a similarmedical image corresponding to the first distribution information in acorresponding display frame among the display frames with an initialdisplay size, in response to detection that the second distributioninformation has been selected, display a similar medical imagecorresponding to the second distribution information in a correspondingdisplay frame among the display frames in such a manner that the similarmedical image corresponding to the second distribution information isenlarged and displayed within the corresponding display frame withrespect to, as a center of enlargement, the corresponding region ofinterest included in the similar medical image corresponding to thesecond distribution information, and in response to detection that thethird distribution information has been selected, display a similarmedical image corresponding to the third distribution information in acorresponding display frame among the display frames in such a mannerthat the similar medical image corresponding to the third distributioninformation is enlarged and displayed within the corresponding displayframe with respect to, as a center of enlargement, the correspondingregion of interest included in the similar medical image correspondingto the third distribution information and in such a manner that thecorresponding region of interest includes the pleura.
 10. The controlmethod according to claim 8, wherein the first distribution informationis information indicating a distribution that belongs to a bilateralcategory, a multiple category, a diffuse category, or a hematogenouscategory, the second distribution information is information indicatinga distribution that belongs to a segmental category or a bronchialcategory, and the third distribution information is informationindicating a distribution that belongs to a subpleural category.
 11. Anon-transitory computer-readable recording medium storing a program forcausing an information terminal to execute a process, the informationterminal accessing a case search system that searches for a medicalimage with reference to a medical image database having medical imagesregistered therein, the information terminal including a display and acomputer, wherein a target medical image that is a medical image to beinterpreted is displayed on the display, the target medical image beingselected from among candidate medical images to be interpreted, theprocess comprising: causing the computer of the information terminal todetect designation information indicating a region of interest includedin the target medical image; causing the computer of the informationterminal to receive from the case search system, in accordance with theregion of interest indicated by the designation information, a pluralityof similar medical images each having a feature value having apredetermined similarity to a feature value of the region of interest,each of the plurality of similar medical images including acorresponding region of interest which corresponds to the region ofinterest; causing the computer of the information terminal to display adisplay screen on the display, the display screen being a screen onwhich a number of similar medical images that is less than or equal to apredetermined value among the received plurality of similar medicalimages are displayed, the display screen including a number of displayframes that is equal to the predetermined value to display the similarmedical images; causing the computer of the information terminal to, inresponse to detection of an instruction for enlarging the similarmedical images being displayed on the display screen, enlarge anddisplay the corresponding regions of interest included in the similarmedical images while maintaining sizes of the display frames unchangedon the display screen; and causing the computer of the informationterminal to, in response to detection of an instruction for causing aselected similar medical image selected from among the enlarged anddisplayed similar medical images to move within a corresponding displayframe among the display frames, cause an unselected similar medicalimage other than the selected similar medical image to movesynchronously with the movement of the selected similar medical imagewithin a display frame corresponding to the unselected similar medicalimage among the display frames in a movement direction identical with amovement direction in which the selected similar medical image moves,wherein a ratio of a movement distance by which the selected similarmedical image moves to a movement distance by which the unselectedsimilar medical image moves corresponds to a ratio of an area of thecorresponding region of interest included in the selected similarmedical image to an area of the corresponding region of interestincluded in the unselected similar medical image.